Kyushu University Academic Staff Educational and Research Activities Database
Researcher information (To researchers) Need Help? How to update
Masahito Shoyama Last modified date:2021.06.14



Graduate School
Undergraduate School
Other Organization
Administration Post
Other


E-Mail *Since the e-mail address is not displayed in Internet Explorer, please use another web browser:Google Chrome, safari.
Homepage
https://kyushu-u.pure.elsevier.com/en/persons/masahito-shoyama
 Reseacher Profiling Tool Kyushu University Pure
http://ees.kyushu-u.ac.jp/~shoyama/
Academic Degree
Effects of Magnetizing Current of the Transformer in the Push-Pull DC-DC Converter
Country of degree conferring institution (Overseas)
No
Field of Specialization
Electronic circuit, Power electronics, Switching Power Supplies, EMC engineering
ORCID(Open Researcher and Contributor ID)
0000-0002-2448-9942
Total Priod of education and research career in the foreign country
01years00months
Outline Activities
Switching power converters are widely used in almost all electronic equipment, but they may cause serious problems by generating switching noise. In this laboratory, many good ideas have been proposed and analyzed to reduce the switching noise.

Research topics:
- Research on circuit technology:
Miniaturization, high-efficiency and low-noise of power converter; Soft switching technology;
LLC Resonant type converter; Bidirectional DC-DC converter; Bidirectional multi-port converter;
Application technology of new semiconductor devices (SiC, GaN)
- Research on control technology:
Digital control; Stabilization and high-speed response technology in bidirectional power control
- Research on applied systems:
Next generation DC power supply system utilizing renewable energy; Plug and play technology;
Automatic power routing with multilevel virtual conductor; HEMS; BEMS;
Power management of electronic equipment;
Power supply for portable electronic equipment; Power supply for lighting
- Noise reduction of bridgeless PFC circuit, motor drive circuit and power conditioning circuit
- Noise reduction of power electronics circuit by the noise cancellation technology
Research
Research Interests
  • Study on Optimal Design Method of New Control Current Resonant Converter
    keyword : LLC current resonance converter, frequency control, phase shift control
    2017.04.
  • Control and stability of DC power supply system using bidirectional DC-DC converter
    keyword : Bidirectional DC-DC Converter, DAB Converter
    2019.04.
  • EMI Modeling and Reduction of Conducted Noise in Switching Power Converters
    keyword : DC-DC Converter, Noise reduction
    2018.04~2020.03.
  • Miniaturization of X-ray high voltage power supply
    keyword : LLC current resonant converter, soft switching
    2017.01.
  • Peak Current Mode Control DC-DC Converter Considering Turn-Off Delay Time
    keyword : Figh-frequency DC-DC Converter, dividing operation mode
    2017.04~2020.03.
  • Bidirectional DC-DC multiport converter for green base station
    keyword : Bidirectional DC-DC Converter, Solar cell, Battery
    2017.04~2019.03.
  • High-speed digital control of current mode DC-DC converter
    keyword : Fast responce, Figh-frequency DC-DC Converter
    2015.10~2020.03.
  • Application of Wireless Electromagnetic Resonance Technology to Rotary Transformer Used in Ultrasonic Spindle
    keyword : Wireless electromagnetic resonance, Rotary transformer
    2014.04~2019.03.
  • Dynamic Characteristics and Controller Design of LLC Current Resonant Converters
    keyword : Noise reduction, Soft switching, High efficiency
    2014.04~2020.03.
  • Noise Recuction Techniques in Inverters for Motor Drives
    keyword : Inverter, Noise reduction
    2014.04.
  • Noise Recuction Techniques in Bridge-less PFC Converters
    keyword : Bridge-less PFC Converter, Noise reduction
    2012.04~2019.03.
  • High Performance Switching Power Supplies by Digital Control
    keyword : Digital Control, Switching Power Supplies
    2014.04~2017.03.
  • Giant Pulse Generator for Laser Ignition
    keyword : Laser Ignition, Current Mode Converter Type Driver
    2015.10~2017.03.
  • Bidirectional DC-DC Converters and Power Supply Systems Using Them
    keyword : Bidirectional DC-DC Converter
    2012.04~2017.03.
  • Research on Low-Noise Topologies in Power Electronics Circuits
    keyword : Low-Noise, Topology, Switching Power Supply, Power Electronics Circuits
    2011.04~2015.03.
  • Research on Circuit Topology of Boost Converter for Hybrid Vehicles
    keyword : Bidirectional converter, Boost converter, Hybrid Vehicle
    2009.09~2011.03.
  • Research on Low-Noise and Hih-Efficiency Power Factor Correction Converters
    keyword : PFC Coverter, Bridgeless PFC, Low-noise, High-efficiency
    2010.04~2014.03.
  • Research on contactless power feeding technology and its applications
    keyword : contactless power feeding, wireless power feeding, electromagnetic resonance, electromagnetic induction
    2010.04~2015.03.
  • Switching Power Supply with Transient Current Circuit
    keyword : switching power supply, soft switching, high-efficiency
    2009.04~2014.03.
  • Cutting Edge Technologies of Soft-Switching
    keyword : switching power supply, soft switching, high-efficiency
    2010.04~2013.03.
  • Power Supply System for MPU in the Next and Next Generation
    keyword : switching power supply, small-size, low-profile, high-efficiency
    2009.10~2010.09.
  • LLC current resonant converters for flat panel displays with small-size, low-profie, high-efficiency and good dynamic characteristics
    keyword : switching power supply, flat panel display, LLC current resonant converter, small-size, low-profile, high-efficiency
    2008.04~2014.03.
  • One-chip power supplies operating at ultra high frequency
    keyword : one-chip power supply, switching power supply
    2008.04~2010.03.
  • Power routing and noise reduction of DC power feeding system
    keyword : DC power feeding system, switching power supply, power routing, noise reduction
    2008.04~2013.03.
  • Software design tools for low-noise switching power supplies
    keyword : switching power supply, noise design, software tool
    2008.04~2011.03.
  • Resonant switched capacitor converter
    keyword : switched capacitor converter, resonant inductor, high efficiency
    2003.04~2007.03Switched capacitor converters, which are based on charge and discharge operation of capacitors, have been used to realize small size and light weight DC-DC converters in various kinds of electronic devices mainly with a light load. However, conventional switched capacitor converters have an inherent drawback that their efficiency is much decreased as the output current is increased. Because this inherent drawback is due to a periodical forced charging and discharging operation in the internal switched capacitors accompanied by a large capacitor current, their efficiency can not be increased by decreasing its internal resistance, e.g. conduction resistance of the switches. So, they are limited to use in a very small output current. We have presented a novel switched capacitor converter topology that uses a resonant operation instead of the forced charging and discharging operation. Its advantage over a conventional switched capacitor converter is a high efficiency even in a high output current region. Its operation analysis and steady-state characteristics habe been shown and confirmed by experiments. As a result, it has been obtained that the resonant switched capacitor converter maintains a high efficiency even in a high output current region..
  • Common mode noise reduction using balanced switching supplies
    keyword : balanced switching supply, common mode conducted noise, current cancellation
    2001.04~2007.03Because conventional switching converters are usually using unbalanced circuit topologies, parastic capacitance between the drain of an MOS-FET and the frame ground through its heat sink may generate the common-mode conducted noise. We have proposed a concept of balanced switching converter circuit, which is an effective way to reduce the comonn-mode cunducted noise of a switching converter by current cancellation. The path of the noise current in a balanced converter circuit has been investigated usung a current probe. By measuring current waveforms and frequency spectra of the parastic capacitances and the frame ground line, the mechanism of the common-mode noise reduction by current cancellation has been clarified..
  • Common mode noise reduction in common source type active clamped DC-DC converters
    keyword : DC-DC converter, active clamped circuit, common mode noise, near field radiated noise
    2001.04~2004.03We have pointed out that the common-source type active-clamp converter has a good feature of common-mode noise reduction and have shown its low noise characteristics. We have analyzed the noise reduction mechanism in the common-source type active-clamp converter in detail. By measuring the near-field magnetic radiated noise, we have examined the noise current path on the converter circuit board at some frequencies in problem. From this analysis we have derived a high-frequency equivalent circuit for conducted noise current..
Current and Past Project
  • LLC power supply circuits are attracting attention as a method suitable for realizing high efficiency and miniaturization of power supplies for ICT and energy management systems, but in practical development, a model of dynamic control characteristics for designing desired dynamic characteristics. The theory for designing circuit parameters to achieve high efficiency and high efficiency has not been established. In this research, we aim to develop a modeling method that expresses dynamic control characteristics and to develop a highly efficient parameter optimization design for resonant circuits.
  • Green base stations, which are being deployed nationwide, have environmental equipment such as lithium-ion batteries, solar panels and fuel cells, and maximize commercial power generation and minimize purchased power while receiving commercial power. It ensures backups in the event of a disaster and reduces power costs. On the other hand, recently, there is an increasing expectation that resilience will be improved in the event of a disaster by utilizing distributed power sources including electric vehicles such as electric vehicles and fuel cell vehicles. It is necessary to establish supply technology. In this research, through research on the hardware configuration and control configuration of a multi-input/output power supply system that achieves optimal cooperation, highly efficient power supply in the event of a disaster, improvement of flexible efficiency during normal times, and introduction of a simple configuration of the power supply system Aim to reduce costs.
  • It aims to be miniaturized by increasing the in-vehicle DC / DC converter to high frequency, and to be built in PCU power stack. Research and development of elemental technologies necessary for it and verification of the feasibility of DC / DC converter are carried out.
  • New control method in order to shorten the design time of the current resonant converter, the optimum design method is clarified.
  • While receiving power, we are maximizing our own generation power and minimizing purchased electric power, realizing backups at the time of disaster and reducing electricity cost. On the other hand, the problem with this system is that it is mainly controlled by a single station, and it is not a bi-directional power exchange in multiple stations or a power supply system configuration that converts power efficiently. In this research, we conduct research on the hardware configuration and control configuration of multi-input / output power system (bidirectional) that combines multiple green equipment and commercial electric power to reduce flexibility and power conversion loss, simplify power system We aim to reduce the introduction cost by configuring.
  • Apply a noise cancellation technique to the motor drive inverter to reduce conduction noise.
  • In this research, we develop and develop ultra compact drivers for laser ignition plug system with innovative circuit technology, from simulation model creation to basic experiment verification and EMC evaluation.
  • We will develop a digital control power supply circuit of soft switching type suitable for high reliability, high efficiency and miniaturization of power supply circuit of ICT equipment such as server and personal computer.
  • Study soft switching circuit technology, magnetic part design method, circuit control method for higher efficiency higher frequency than conventional level, implement countermeasure planning / prototype evaluation. Also investigate and examine which application the constructed technology / method can be applied.
  • It aims at research on a new generation power supply circuit and control method with low noise compared with the conventional method. Murata Manufacturing Proposal We will conduct prototype and demonstration evaluation of low noise novel generation power circuit and control method and research on its characteristics.
  • Study on compact feasibility of X-ray high voltage power supply using SiC and research on high voltage circuit to replace Cockcroft · Walton circuit.
Academic Activities
Books
1. Emad M. Ahmed, Masahito Shoyama, Maximum Power Point Tracking (MPPT) in photovoltaic (PV) Systems: Converter Topology, Tracking algorithms, Simulation and Experimental Results, (財)北九州国際技術協力会(KITA)主催 国際協力機構(JICA)研修, 「太陽光エネルギー発電技術コース」, 2012.03.
Papers
1. Toshiya Tadakuma, Michael Rogers, Koichi Nishi, Motonobu Joko, Masahito Shoyama, Impact for Radiated Noise by Current Smoothness with Bare SiC MOSFET and Si RC-IGBT Chips, 2021 JOINT IEEE INTERNATIONAL SYMPOSIUM ON ELECTROMAGNETIC COMPATIBILITY, SIGNAL & POWER INTEGRITY, EMC EUROPE, 2021.08.
2. M. S. Hassan, Ahmed Abdelhakim, Masahito Shoyama, Jun Imaoka, Gamal M. Dousoky, Parallel Operation of Split-Source Inverters for PV Systems: Analysis and Modulation for Circulating Current and EMI Noise Reduction, IEEE Transactions on Power Electronics, 10.1109/TPEL.2021.3052676, 36, 8, 9547-9564, 2021.08, To satisfy the ever-increasing requirement from load side and improve the power quality through harmonic content reduction, the paralleled converters’ structure is seen to be an interesting solution. However, paralleled converters, in which the same dc and ac sides are shared, suffer from a major challenge related to the excessive circulating currents due to the difference in the induced common-mode voltage (CMV) in each converter. This voltage difference is due to the instantaneous potential difference between paralleled phase-legs, due to the discrepancy in circuit and control parameters of paralleled converters. Consequently, zero-sequence circulating current (ZSCC) as well as differential-mode circulating current (DMCC) shall appear between the paralleled converters. In this context, this article utilizes the interleaved pulsewidth modulation (PWM) concept for the ZSCC and DMCC reduction in paralleled split-source inverters (SSIs), where this SSI is a single-stage dc–ac converter and the prior mentioned operation and associated issues have not been investigated yet. This article describes the three-phase SSI structure and its basic operation, and shows the corresponding CMV waveform. Then, based on the shown analysis, an interleaved discontinuous PWM strategy is proposed to restrain the CMV amplitude and reduce the induced circulating currents. Furthermore, the effect of changing the modulation index and interleaving angle on the overall converter behavior has also been evaluated in case of using SSI. The analysis and simulations revealed the effectiveness of the proposed modulation strategy compared to counterparts. Finally, the shown simulation results are validated with an experimental prototype of 1 kW..
3. M. S. Hassan, Ahmed Abdelhakim, Masahito Shoyama, Gamal M. Dousoky, On-the-analysis and reduction of common-mode voltage of a single-stage inverter through control of a four-leg-based topology, ELSEVIER International Journal of Electrical Power & Energy System, 10.1016/j.ijepes.2020.106710, 127, 1-24, 2021.05, This paper presents a three-phase four-leg-based split-source inverter (SSI) topology to reduce its instantaneous common-mode (CM) voltage. The proposed topology utilizes a simple discontinuous pulse width modulation (DPWM) strategy based on imaginary switching times (ISTs) with a single Boolean logic gate to drive the fourth leg. The paper first presents a brief analysis of the CM voltage issue in the available SSI equipped with different control techniques. Then, the principle of operation and the analysis of the proposed four-leg-based SSI topology along with the proposed modulation technique are introduced. Moreover, the output filter inductance’s effect on the CM voltage levels is examined and the results are provided. To verify the effectiveness and demonstrate the performance of the proposed inverter topology with the associated modulation strategy, a Simulink model has been designed, evaluated and then verified with experiments with different case studies and modulation strategies. The obtained results show that the proposed four-leg-based SSI with the proposed modulation strategy not only restrains the instantaneous peak-to-peak CM voltage but also reduces the number of switching transitions in the resultant CM voltage..
4. Toshiya Tadakuma, Michael Rogers, Koichi Nishi, Motonobu Joko, Masahito Shoyama, Carrier Stored Layer Density Effect Analysis of Radiated Noise at Turn-On Switching via Gabor Wavelet Transform, IEEE Transactions on Electron Devices, 10.1109/TED.2021.3061492, 68, 4, 1827-1834, 2021.04, The basic IGBT structure was reported about 40 years ago and has become more complex to achieve lower losses, higher robustness, higher reliability, and cost-effectiveness. Today’s power devices are also required to improve noise characteristics corresponding to its increasing switching speed. In noise analysis based on switching waveforms, Fourier transform (FT) is often applied to estimate the causes as device structure has frequently been improved. However, the time information is implicitly deleted according to FT, and it is difficult to consider the causes by extraction of specific parts on waveforms because every waveform’s time axis includes important information for device structures. This article presents analysis methodology to identify the key parts without deleting time information by using a wavelet transform and elucidates the effect of transition of dominant radiated noise generated at turn-on operation in case of different carrier stored layer density in CSTBTs..
5. Shuaitao Zhang, Qiang Lin, Yuichi Noge, Masahito Shoyama, Eiji Takegami, Gamal M. Dousoky, Developed Common Mode Noise Modeling Approach for DC-DC Flyback Converters, IEEE Letters on Electromagnetic Compatibility Practice and Applications, Vol. 2, Iss. 4, pp. 147-151, 2020.12.
6. Shuaitao Zhang, Qiang Lin, Baihua Zhang, Masahito Shoyama, Eiji Takegami, Analysis and Improvement of Impedance Balancing Technique for Common Mode Noise Mitigation, IEEE IPEMC 2020-ECCE Asia, 3277-3283, 2020.11.
7. Qiang Lin, Shuaitao Zhang, Baihua Zhang, Masahito Shoyama, Balanced Technique for Common Mode EMI Suppression in Transformer-less PV Systems, IEEE IPEMC 2020-ECCE Asia, 1900-1904, 2020.11.
8. Shuaitao Zhang, Qiang Lin, Yuichi Noge, Masahito Shoyama, Eiji Takegami, Gamal M. Dousoky, Developed Common Mode Noise Modeling Approach for DC-DC Flyback Converters, IEEE GEMCCON 2020, 1-4, 2020.10.
9. Hideaki Funaki, Atsushi Mishima, Masahito Shoyama, Tomonori Kimura, Takahiro Yamada, Gamal M. Dousoky, A Condition to Get Rid of Slope-Compensation in Peak-Current-Mode Controllers, 12th Annual IEEE Energy Conversion Congress and Exposition, ECCE 2020 2020 IEEE Energy Conversion Congress and Exposition, ECCE 2020, 10.1109/ECCE44975.2020.9236378, 3580-3586, 2020.10, Current-mode control is used in Switched-Mode Power Supplies (SMPSs) due to its high stability and quick response. Moreover, peak current-mode control, as one of the current-mode control techniques is often used due to its ease of design and capability of overcurrent protection. However, peak current-mode control sometimes makes output oscillations in certain conditions. Accordingly, SMPSs designers often use slope compensation to prevent output oscillation. However, it has some challenges such as design complexity and delayed response. Therefore, in this research, the authors derived a conditional expression to replace the use of slope compensation based on multi-cycle digital control. The proposed quantity along with its derivation is provided in this manuscript. Furthermore, the carried-out investigations validate its applicability..
10. M. S. Hassan, Ahmed Abdelhakim, Masahito Shoyama, Jun Imaoka, Gamal M. Dousoky, Three-Phase Split-Source Inverter-Fed PV Systems: Analysis and Mitigation of Common-Mode Voltage, IEEE Transactions on Power Electronics, 10.1109/TPEL.2020.2971374, 35, 9, 9824-9838, 2020.09, Common-mode voltage (CMV), caused by standard high-frequency pulsewidth modulated (PWM) voltage source inverters (VSIs), is a major area of interest in various applications, such as electric motor drives, transformerless photovoltaic systems, and grid-tied inverters. Since VSIs have only the buck capability during the inversion mode, an additional boosting stage either in the dc side or in the ac side has to be utilized for low-voltage-fed applications. On the other hand, single-stage solutions, with buck and boost capabilities, represent an interesting alternative with reduced cost, complexity, and converter volume. Among the possible single-stage solutions, split-source inverter (SSI), which has been recently proposed, has several merits over its counterparts. One of the questionable aspects concerning this topology is the CMV, which has not been investigated yet. This article examines the induced CMV with the SSI. This is done by examining the CMV waveforms for VSI and SSI topologies, and then, comparing each other under different PWM schemes. Furthermore, this article proposes the use of the discontinuous space vector PWM scheme with the SSI to mitigate the CMV, where the analysis shows a significant reduction in the CMV compared to the other schemes. In order to validate the introduced analysis, simulation model has been designed using MATLAB/Simulink environment, and simulation results are presented. Moreover, a prototype has been built-up for testing the proposed concepts and the obtained experimental results are provided..
11. Mokhtar Aly, Emad M. Ahmed, Masahito Shoyama, Modulation Method for Improving Reliability of Multilevel T-Type Inverter in PV Systems, IEEE Journal of Emerging and Selected Topics in Power Electronics, 10.1109/JESTPE.2019.2898105, 8, 2, 1298-1309, 2020.06, Multilevel inverters (MLIs) have proven superior performance in several applications, especially in photovoltaic (PV) applications. However, power switches in MLIs possess high failure rates due to unequal power losses distributions that shorten lifetime of the whole PV inverter. Therefore, a new pulsewidth modulation (PWM) methodology for loss balance in grid connected PV single-phase five-level inverters is presented in this paper. The proposed loss balance PWM (LBPWM) method is based on swapping the utilization of power switches through half or quarter of the fundamental line period based on the redundancies between the switching states in MLIs. In addition, the proposed LBPWM method achieves natural balance among voltages over the dc-link capacitors. The effectiveness and feasibility of the proposed LBPWM method are verified using the simulation environment and experimental prototype. Different operating conditions and points of PV inverters are investigated in addition to reliability evaluation of the PV inverter are provided. Moreover, the superior performance criterion of the proposed LBPWM methods are verified through comprehensive comparisons with the most prominent previously developed PWM methods in the literature. The generalization and implementation steps of the proposed LBPWM method are also provided..
12. Ahmed A.Zaki Diab, Hamdy M. Sultan, Raseel Aljendy, Ameena Saad Al-Sumaiti, Masahito Shoyama, Ziad M. Ali, Tree Growth Based Optimization Algorithm for Parameter Extraction of Different Models of Photovoltaic Cells and Modules, IEEE Access, 10.1109/ACCESS.2020.3005236, 8, 119668-119687, 2020.06, Among all renewable energy sources, solar cells are considered the most popular solution for a clean source of energy and have a wide range of applications from few watts to Megawatt industrial and domestic loads. Building a precise mathematical model based on nonlinear equations for solar cells as well as photovoltaic (PV) modules is an essential issue for reasonable performance assessment, control and optimal operation of PV energy systems. In the current study, a novel optimization algorithm, Tree Growth Algorithm (TGA), is applied for accurate and efficient extraction of the unknown solar cell and PV module parameters. TGA is applied for estimating the unidentified parameters of PV models. Single diode model (SDM), double diode model (DDM) and three diode model (TDM) are investigated in the mathematical models of both solar cells and PV modules. The obtained results from the application of TGA to achieve this objective are compared with different algorithms reported in the literature. Moreover, the results demonstrated that the proposed algorithm of TGA superior to other reported methods. The good matching of the I-V characteristic curve of the computed parameters with those of the measured data from the manufacturer's PV modules/cells datasheet proved that the proposed TGA may function as a competitor to the methods provided in literature for parameters' identification of PV of solar cells..
13. Toshiya Tadakuma, Michael Rogers, Koichi Nishi, Masahito Shoyama, Dominant Timing Direct Identification for Radiation Noise due to Extended Double Pulse Test on Bare SiC MOSFET and Si RC-IGBT Chips, 2020 IEEE International Symposium on Electromagnetic Compatibility & Signal/Power Integrity, EMCSI 2020, 10.1109/EMCSI38923.2020.9191602, 73-78, 2020.06.
14. Shuaitao Zhang, Baihua Zhang, Qiang Lin, Eiji Takegami, Masahito Shoyama, Gamal M. Dousoky, Modeling and optimization of impedance balancing technique for common mode noise attenuation in DC-DC boost converters, Electronics (Switzerland), 10.3390/electronics9030480, 9, 3, Vol. 9, Iss. 3, pp. 1–16, 2020.03, As an effective means of suppressing electromagnetic interference (EMI) noise, the impedance balancing technique has been adopted in the literature. By suppressing the noise source, this technique can theoretically reduce the noise to zero. Nevertheless, its effect is limited in practice and also suffers from noise spikes. Therefore, this paper introduces an accurate frequency modeling method to investigate the attenuation degree of noise source and redesign the impedance selection accordingly in order to improve the noise reduction capability. Based on a conventional boost converter, the common mode (CM) noise model was built by identifying the noise source and propagation paths at first. Then the noise source model was extracted through capturing the switching voltage waveform in time domain and then calculating its Fourier series in frequency domain. After that, the conventional boost converter was modified with the known impedance balancing techniques. This balanced circuit was analyzed with the introduced modeling method, and the equivalent noise source was precisely estimated by combining the noise spectra and impedance information. Furthermore, two optimized schemes with redesigned impedances were proposed to deal with the resonance problem. A hardware circuit was designed and built to experimentally validate the proposed concepts. The experimental results demonstrate the feasibility and effectiveness of the proposed schemes..
15. M. S. Hassan, Ahmed A. Zaki Diab, Masahito Shoyama, Gamal M. Dousoky, Interleaved PWM Strategy for Common-Mode Leakage Current and EMI Noise Reduction of Paralleled Single-Stage DC-AC Converters, 35th Annual IEEE Applied Power Electronics Conference and Exposition, APEC 2020 APEC 2020 - 35th Annual IEEE Applied Power Electronics Conference and Exposition, 10.1109/APEC39645.2020.9124053, 768-774, 2020.03, Investigating the common-mode voltage (CMV) is a continuing concern in power electronic inverter, due to the fact that the desired sinusoidal waveforms cannot be obtained from a typical voltage source inverter (VSI). Such difficulty in producing these sinusoidal waveforms is due to the continuous generation of power pulses produced by the pulse width modulation (PWM) strategy applied to the switching devices in inverter legs. In this context, this paper utilizes the interleaved PWM concept for the CMV reduction of paralleled single-stage dc-ac split-source inverters (SSI). Firstly, the conventional SSI structure and basic operation are described and the corresponding CMV waveform is discussed. Then, based on the analysis, the interleaved PWM strategy is proposed in order to restrain the instantaneous CMV peaks, reduce the induced common-mode (CM) leakage current (CMLC), and attenuate the electromagnetic interference (EMI) noise spectra as well. In addition to that, the impact of various interleaved angles is also investigated. Finally, simulation using Simulink models are used to verify the proposed concepts..
16. Mokhtar Aly, Emad M. Ahmed, Samir Kouro, Masahito Shoyama, Capacitor Voltage Ripple Reduction Modulation Method for String Photovoltaic Inverters, 21st International Middle East Power Systems Conference, MEPCON 2019 2019 21st International Middle East Power Systems Conference, MEPCON 2019 - Proceedings, 10.1109/MEPCON47431.2019.9008065, 852-857, 2019.12, This paper proposes a new pulse width modulation (PWM) method for reducing capacitor voltage ripples in H-bridge five-level T-Type inverters for grid-connected single-phase photovoltaic (PV) string inverter applications. The T-Type inverters have been widely employed in several applications due to their superior performance. However, single-phase applications suffer from high voltage ripples over the dc-link capacitors. These ripples cause shortened operating lifetime and reduced reliability of capacitors in addition to distorted output current of the inverter. Thence, a new improved PWM method is developed in this paper for reducing the ripple voltages over the capacitors. The new PWM method employs equally swapped utilization of dc-link capacitors within the line period. In addition, the proposed method is capable of achieving natural voltages balancing among the capacitors. The simulation and experimental verifications of the new proposed PWM have been provided..
17. Masaki Nakamura, Kazuhiko Takeno, Ryota Hisamitsu, Masahito Shoyama, Bi-directional multiport converter for utilizing green base stations as virtual power plant, 8th International Conference on Renewable Energy Research and Applications, ICRERA 2019 8th International Conference on Renewable Energy Research and Applications, ICRERA 2019, 10.1109/ICRERA47325.2019.8996536, 137-141, 2019.11, In recent years, virtual power plant mechanisms that contribute to adjusting the power supply and demand by integrating and controlling energy resources on the customer side have drawn attention. On the other hand, NTT DOCOMO has deployed Green Base Station(G-BTS) equipped with solar panels and high-capacity, high-density lithium-ion batteries, and is working on securing backup in the event of a disaster and reducing power costs. In this paper, in order to use the G-BTS as a virtual power plant, we examined the system configuration and control method that assumed the power cooperation between multiple stations, and confirmed the various operations required for the power cooperation by the actual machine verification..
18. Ahmed A.Zaki Diab, M. S. Hassan, Masahito Shoyama, Modified Adaptive Sliding Mode Control for Sensorless Direct-Drive Permanent Magnet Synchronous Generator Wind Turbines based on Fuzzy Logic Control, 4th IEEE International Future Energy Electronics Conference, IFEEC 2019 2019 IEEE 4th International Future Energy Electronics Conference, IFEEC 2019, 10.1109/IFEEC47410.2019.9015138, 2019.11, This paper presents a modified adaptive sliding mode controller (MASMC) to control the machine side converter of sensorless direct-drive permanent magnet synchronous generator (PMSG) wind Turbines. The MASMC is applied to control the components of stator currents in the synchronous reference frame of PMSG. The proposed MASMC involves two integral switching functions for controlling direct and quadrature stator currents components. Moreover, a modified adaptive sliding mode observer (MSMO) has been implemented in order to estimate the rotor position and speed. In the MASMC, the low pass filter in the conventional sliding mode observer (SMO) has been eliminated in order to eliminate its problems. The parameters of MSMC have been adapted based on the fuzzy logic to overcome the poor dynamic performance of the constant parameters. In order to test the proposed control scheme, simulations using MATLAB/Simulink have been carried out. Moreover, the validation of the proposed controller has been done by comparing its performance with the performance of PI controller. The simulation results demonstrate the effectiveness of the proposed control system..
19. Eltaib Abdeen, Mahmoud A. Gaafar, Mohamed Orabi, Masahito Shoyama, Three Level T-Type Buck-Boost Voltage Source Inverter, 2019 IEEE Conference on Power Electronics and Renewable Energy, CPERE 2019 IEEE Conference on Power Electronics and Renewable Energy, CPERE 2019, 10.1109/CPERE45374.2019.8980233, 175-180, 2019.10, This paper presents a three level T-type buck-boost voltage source inverter (3LT2-BBVSI) to be used with distributed generation systems. The 3LT2-BBVSI topology combines a three level T-type inverter with DC-DC boost converter in one power stage; thus, high boosting gain along with multi-level shaping of the output voltage are acquired. Compared to other single-stage boost inverters, the proposed one achieves significant reduction in the passive components count; thus, reduced size along with higher efficiency can be realized. In this paper, the topology description along with the steady state analysis are presented. The operation of LT2-BBVSI is verified using OPAL-RT LAB tools. In addition, experimental results using 3LT2-BBVSI prototype are introduced..
20. Jun Imaoka, Kenkichiro Okamoto, Masahito Shoyama, Yuki Ishikura, Mostafa Noah, Masayoshi Yamamoto, Modeling, Magnetic Design, Simulation Methods, and Experimental Evaluation of Various Powder Cores Used in Power Converters Considering Their DC Superimposition Characteristics, IEEE Transactions on Power Electronics, 10.1109/TPEL.2018.2886044, Volume 34, Issue 9, pp. 9033-9051, 2019.09, Powder cores have been gaining much attention as one of the attractive magnetic cores used in power converters due to their superior features such as high saturation flux density and their capability to suppress fringing flux due to the distributed air gaps. However, powder cores have a unique feature that the relative permeability of the magnetic core varies depending on the magnetic field intensity. The comprehensive modeling of variable relative permeability, design method of powder cores, and computer simulation methods are not well-discussed in the relevant literature. This paper proposes a novel modeling, magnetic design method, and simulation technique considering dc superimposition characteristics of powder cores. The modeling method relies on a simple novel model equation representing the behavior of the variable relative permeability under the dc current superimposition condition, which is helpful to evaluate the performance of powder cores and to properly design various magnetic components. In this evaluation, five different magnetic powder cores are used to show the accuracy and properness of the proposed method. Theoretical analysis has been presented and the effectiveness of the proposed methods has been evaluated through simulation and experimental tests..
21. M. S. Hassan, Masahito Shoyama, Pulse Width Modulation-Based Common-Mode Noise Source Characterization of Three-Phase Two-Level Split-Source Inverter, 11th Annual IEEE Energy Conversion Congress and Exposition, ECCE 2019 2019 IEEE Energy Conversion Congress and Exposition, ECCE 2019, 10.1109/ECCE.2019.8911837, 2867-2872, 2019.09, Several undesirable impacts of electromagnetic interference (EMI) have been reported in various applications including not only motor drives but also transformerless photovoltaic (PV) power systems and other applications. These impacts are predominantly due to the converter's noise source voltage that may lead to higher motor bearing currents and inevitably lead to premature damage. In addition to serious leakage currents in non-isolated grid connected PV systems. In this context, this paper presents the analysis and characterization of the noise source spectra of the commonmode (CM) voltage for a single-stage split-source inverter (SSI) topology incorporating three pulse width modulation (PWM) strategies. The mathematical modeling of the investigated modulation techniques is identified, and the induced noise source voltage is examined. Moreover, the resultant noise source spectra are compared, and the main findings are demonstrated. A MATLAB/Simulink model is used to verify the analysis. It is shown that a significant reduction in the noise source spectra can be attained by applying the proposed modulation strategy especially in the high frequency range, which mainly due to the reduced number of transitions in the noise source voltage profile..
22. Shuaitao Zhang, Baihua Zhang, Masahito Shoyama, Develop Common-Mode Conducted Noise Modeling Methodology with Terminal Port Theory, 13th IEEE International Conference on Power Electronics and Drive Systems, PEDS 2019 2019 IEEE 13th International Conference on Power Electronics and Drive Systems, PEDS 2019, 10.1109/PEDS44367.2019.8998806, 2019.07, Based on the terminal port theory, this paper has proposed a common-mode conducted noise modeling method. Single-phase inverter is chosen as an illustrative example. The T-type model has been supposed as the internal structure of the terminal port, according to its features of CM impedance and the noise propagation route. The details of equivalent noise source are given and its accuracy has been verified by comparing with the concept definition. With this model, the effectiveness of the filter could be predicted quickly and accurately. The interaction effect between the EMI filter and harmonic filter has also been viewed in this paper. Theoretical analysis and experimental results are presented to verify this modeling methodology..
23. M. Nakamura, K. Takeno, M. Shoyama, Electric Load Leveling Method for Green Base Station, 13th IEEE International Conference on Power Electronics and Drive Systems, PEDS 2019 2019 IEEE 13th International Conference on Power Electronics and Drive Systems, PEDS 2019, 10.1109/PEDS44367.2019.8998867, 2019.07, Reducing the power consumed by base stations is an urgent requirement. Our research shows that it is possible to reduce electricity consumption, especially peak loads, by electric load leveling method. This approach is implemented in the Green Power Controller, a technique developed for the Green Base Station, which is the power system of base stations used for disaster relief and reducing energy costs. Trials of an implemented controller confirm that the control proposal is effective in reducing electricity consumption by suppressing the peaks in electric power consumption. In anticipation of electricity-network liberalization and accompanying power reforms, we will consider the role of the Green Power Controller and develop even more effective electricity rate reduction measures..
24. Yuto Watase, Shuichi Nakamuta, Baihua Zhang, Masahito Shoyama, Common mode noise cancellation by two opposite-phase-operating inverters for motor drive, 10th International Conference on Power Electronics - ECCE Asia, ICPE 2019 - ECCE Asia ICPE 2019 - ECCE Asia - 10th International Conference on Power Electronics - ECCE Asia, 2179-2184, 2019.05, In motor drive inverters, the switching operations associated with rapid voltage potential change, and flows through parasitic capacitors may cause serious conducted common noise problems. The conducted noise emission introduces interference to other circuits, and therefore should be reduced. In this paper, a technique to suppress common-mode conducted noise is proposed that two inverters are operated in opposite phase. They generate opposite phase common-mode noise, and therefore the noise can be cancelled. The effectiveness of the proposed method is verified by experiments and simulations..
25. Shuaitao Zhang, Baihua Zhang, Masahito Shoyama, Modeling and Prediction of Common-Mode Conducted Noise in Boost Converter with Terminal Port Theory, 10th International Conference on Power Electronics - ECCE Asia, ICPE 2019 - ECCE Asia ICPE 2019 - ECCE Asia - 10th International Conference on Power Electronics - ECCE Asia, 2211-2216, 2019.05, This paper presents a common-mode conducted modeling method with terminal port theory and applied it to boost converter. With no need to measure and analyze the voltage between MOSFET switch directly, this method can obtain the equivalent noise source accurately by utilizing the common-mode current. Then an equivalent common mode model is proposed based on the boost converter according to the features of its noise propagation loop. The accuracy of impedance measurement has also been improved by utilizing interpolation method. In order to examine the validity and robustness of this model, several kinds of filter circuits have been employed and the prediction results show conformability with the experimental results..
26. Baihua Zhang, Shuaitao Zhang, Henan Li, Masahito Shoyama, Eiji Takegami, An Improved Simple EMI Modeling Method for Conducted Common Mode Noise Prediction in DC-DC Buck Converter, IEEE ICDCM 2019, 1-6, 2019.05.
27. M. S. Hassan, Masahito Shoyama, Common-Mode Voltage Investigation and Reduction of Split-Source Inverter, 6th IEEE International Conference on Smart Grid, icSmartGrids 2018 6th IEEE International Conference on Smart Grid, icSmartGrids 2018, 10.1109/ISGWCP.2018.8634437, 118-122, 2019.02, Common mode voltage (CMV), produced by conventional high-frequency pulsewidth modulated (PWM) voltage source inverters (VSIs), is a major area of interest in applications such as transformerless Photovoltaic (PV) systems, electric motor drives, as well as grid-connected inverters. Since the VSI can only be utilized as a buck inverter, the AC output voltage should be boosted up using an extra boosting stage either in the DC side or in the AC side. So, to reduce the cost, complexity, size, and weight of the converter, the additional boosting stage must be eliminated by using single-stage DC-AC converters, which have the buck-boost feature in a single stage. This paper investigates the induced CMV issue due to a recent single-stage DC-AC inverter topology, split-source inverter (SSI), which has not been comprehensively examined. The CMV waveforms for both VSI and SSI have been analyzed and compared. Furthermore, the paper proposes a discontinuous PWM (DPWM) to alleviate the CMV effect. To check the validity of the proposed analysis, simulations were done using MATLAB/Simulink model. It was shown that a significant CMV reduction could be achieved using the proposed modulation technique..
28. Baihua Zhang, Shuaitao Zhang, Masahito Shoyama, Eiji Takegami, A simple conducted noise modeling method for DC-DC converters with accurate noise source model, Research Reports on Information Science and Electrical Engineering of Kyushu University, 24, 1, 9-15, 2019.01, In this study, a simple conducted noise modeling method based on classical frequency domain modeling concept is developed. Compared with conventional methods, the accuracy of noise source model in the proposed modeling method is improved by using S-shape waveform model with the consideration of high frequency ringing waveforms. The parameters of noise source model are extracted on the basis of experimental measured waveforms. Finally, the accuracy of the proposed conducted noise modeling method is validated on a DC-DC boost converter, the comparison between measured and calculated conducted noise spectra show that the low frequency (0.15 MHz-2 MHz) noise peaks as well as high frequency (10 MHz-30MHz) peak can be accurately predicted..
29. M. S. Hassan, Masahito Shoyama, Common-mode noise evaluation study of two-level voltage source inverter using bus-clamping discontinuous PWM strategies, 2018 IEEE International Telecommunications Energy Conference, INTELEC 2018 2018 IEEE International Telecommunications Energy Conference, INTELEC 2018 - Proceedings, 10.1109/INTLEC.2018.8612306, 2019.01, For the common-mode (CM) noise reduction, many literatures have been reported on CM noise reduction using filters, passive or active, and impedance balancing which in both cases, extra devices needed to be added to the circuit that may increase not only the size of the system but also its cost. However, for different pulse width modulation (PWM) techniques, very few studies are available with the perspective of the conducted CM noise as well as common-mode voltage (CMV) reduction in spite of their cost-effective and flexible control advantages. This paper investigates the effect of different Bus-clamping PWM (BCPWM) techniques on the CMV, CM leakage current as well as electromagnetic interference (EMI) noise behavior due to fast switching power devices used in power electronic converters. Conventional space vector PWM (CSVPWM) as well as BCPWM principles are reviewed and their switching sequences are summarized. Timedomain simulations followed by frequency-domain analysis using Fast-Fourier Transform (FFT) algorithm have been carried out and results are presented. It was determined that, the CMV and its subsequent CM noise can be reduced using BCPWM techniques..
30. Shungo Sakamoto, Masahito Shoyama, Configuration and control method of bi-directional multiport converter for DC power supply system, 2018 IEEE International Telecommunications Energy Conference, INTELEC 2018 2018 IEEE International Telecommunications Energy Conference, INTELEC 2018 - Proceedings, 10.1109/INTLEC.2018.8612428, 2019.01, This paper propose bi-directional multiport converter as one of the DC power supply system suitable for renewable energy. The seamless power transmission within a certain voltage range can be realized by using bi-directional multiport converter. Moreover, a circuit configuration and control method of bi-directional multiport converter are included. The effectiveness of the proposed converter and control method has been investigated analytically by simulation and experiment on power transmission..
31. Baihua Zhang, Qiang Lin, Jun Imaoka, Masahito Shoyama, Satoshi Tomioka, Eiji Takegami, EMI prediction and reduction of zero-crossing noise in totem-pole bridgeless PFC converters, Journal of Power Electronics, 10.6113/JPE.2019.19.1.278, 19, 1, 278-287, 2019.01, In this study, a zero-crossing spike current issue in a totem-pole bridgeless power factor correction (PFC) converter is comprehensively investigated for the first time. Spike current occurs when input voltage crosses zero, becomes a noise source, and causes severe common mode emission issues. A generation mechanism for electromagnetic interference (EMI) is presented to investigate the EMI problem caused by zero-crossing issue, and a noise spectrum due to this issue is predicted by a theoretical analysis based on the Fourier coefficient of an approximate spike current waveform. Furthermore, a noise reduction method is proposed and then improved to reduce the spike current. Experimental measurements are implemented on a GaN-based totem-pole bridgeless PFC converter, and the spike current can be effectively suppressed through the proposed method. Furthermore, the noise spectrums measured without and with the reduced zero-crossing spike current are compared. Experimental results validate the analysis of the noise spectrum caused by the zero-crossing spike current issue..
32. Hegazy Rezk, Mokhtar Aly, Mujahed Al-Dhaifallah, Masahito Shoyama, Design and Hardware Implementation of New Adaptive Fuzzy Logic-Based MPPT Control Method for Photovoltaic Applications, IEEE Access, 10.1109/ACCESS.2019.2932694, 7, 106427-106438, 2019.01, An adaptive fuzzy logic (FL)-based new maximum power point (MPP) tracking (MPPT) methodology for controlling photovoltaic (PV) systems is proposed, designed, and implemented in this paper. The existing methods for implementing FL-based MPPTs lack for adaptivity with the operating point, which varies in wide range in practical PV systems with operating irradiance and ambient temperature. The new proposed adaptive FL-based MPPT (AFL-MPPT) algorithm is simple, accurate, and provides faster convergence to optimal operating point. The effectiveness and feasibility verifications of the proposed AFL-MPPT methodology are validated with considering various operating conditions at slow and fast change of solar radiation. In addition, the simplified implementation of the proposed algorithm is carried out using C-block in PSIM software environment, wherein the proposed algorithm and system are simulated. Additionally, experimental results are performed using a floating-point digital signal processing (DSP) controller (TMS320F28335) for verifying the feasibility of the proposed AFL-MPPT methodology. The results of simulations and experimental prototypes show great consistency and prove the capability of the new AFL-MPPT methodology to extract MPPT rapidly and precisely. The new proposed AFL-MPPT method achieves accurate output power of the PV system with smooth and low ripple. In addition, the new proposed AFL-MPPT method benefits fast dynamics and it reaches steady state within 0.01 s..
33. Sultan I. EL-Ajmi, Yehia S. Mohamed, Masahito Shoyama, Ahmed A. Zaki Diab, Optimal design of wind energy system interconnected with utility grid-case study of Egypt, International Journal of Engineering Research and Technology, 12, 9, 1561-1566, 2019.01, This paper presents the optimal design and operation of Wind Energy System (WES) interconnected with Utility Grid (UG). Moreover, the paper introduces a proposed computer program to determine the optimal design of WES to be interconnected with UG. The proposed computer program has been designed to determine the optimum number of Wind Turbine Generators (WTGs) needed to feed a certain load. Many WTG types have been introduced to the computer program to choose the best type of WTG. By using the proposed computer program, the WES components can be completely designed to be interconnected with UG. This program has a subroutine which by using it the optimum operation of WES can be determined hour by hour through the year. Then, the monthly surplus energy, monthly deficit energy and yearly purchase from UG or selling energy to UG can be estimated. The decision from the computer program is based on the minimum price of the generated kWh from the WES. The proposed computer program has been applied on two Egyptian sites. The first sit is Ras- Ghareb which located at the coast of the Red sea and the second site is Ras- EL-Hekma which located at the coast of the Mediterranean Sea..
34. Mokhtar Aly, Emad M. Ahmed, Masahito Shoyama, Ageing Mitigation Control Method for Power Devices in Multilevel Inverters in Standalone PV Systems, 10th Annual IEEE Energy Conversion Congress and Exposition, ECCE 2018 2018 IEEE Energy Conversion Congress and Exposition, ECCE 2018, 10.1109/ECCE.2018.8557707, 5737-5741, 2018.12, Multilevel inverters (MIs) have become widely used in photovoltaic (PV) systems for their high efficiency, reduced leakage currents, and reduced EMI levels. Although MIs suffer from unequal thermal stresses in power devices that lead to aging of power device with their continuous operation. Therefore, this paper proposes a new aging mitigation control (AMC) method to enhance the reliability of MIs against the aging effects in power devices. The operation of the proposed AMC method has three operating modes that are adapted according to the level and type of aging. In small and medium aging levels, the proposed method preserves the full output power ratings of the inverter with maximum energy extraction from PV modules. Whereas, in high aging level region and multiple devices failures, the proposed method reduces the output power so as to maintain continuous operation of the inverter without harmful consequences. The simulation and experimental results with comparisons to conventional methods show effective performance of the proposed AMC method..
35. Atsushi Mishima, Reo Takiguchi, Jun Imaoka, Masahito Shoyama, Akihiro Yamaguchi, Tomonori Kimura, Current-Mode Digital Control Method for High Frequency DC-DC Converter with Reduced Number of Sampling in One Switching Cycle, 10th Annual IEEE Energy Conversion Congress and Exposition, ECCE 2018 2018 IEEE Energy Conversion Congress and Exposition, ECCE 2018, 10.1109/ECCE.2018.8557393, 1423-1427, 2018.12, In recent years, switching frequency of Switched-Mode Power Supplies (SMPS) has been getting higher and digital control circuits are adopted for the purpose of downsizing and weight reduction. In addition, current-mode control has attracted attention because of its advantages: high speed response and high stability. However, it is difficult to realize current-mode control with digital control circuit that needs to grasp current behavior in real time because sampling frequency is not enough high for switching frequency. In this paper, we will propose a novel current-mode digital control method that predict current behavior with output voltage and previous current sampling data of SMPS and prove its effectiveness in simulation..
36. Mokhtar Aly, Emad Ahmed, Masahito Shoyama, A New Single Phase Five-Level Inverter Topology for Single and Multiple Switches Fault Tolerance, IEEE Transactions on Power Electronics, Volume 33, Issue 11, pp. 9198-9208, 2018.11.
37. Jun Imaoka, Masahito Shoyama, A Leakage Flux Cancellation Technique for Series-Parallel Combined Resonant Circuits with Asymmetric Rotary Transformers Used for Ultrasonic Spindle Drive, 8th International Power Electronics Conference, IPEC-Niigata - ECCE Asia 2018 2018 International Power Electronics Conference, IPEC-Niigata - ECCE Asia 2018, 10.23919/IPEC.2018.8507729, 1554-1561, 2018.10, This paper proposes a novel leakage flux cancellation technique suitable for series-parallel combined resonant circuits with asymmetric rotary transformer used for ultrasonic spindles drive. An asymmetric rotary transformer is utilized in the ultrasonic spindle in order to realize automated tool change. However, an asymmetric rotary transformer is likely to occur much leakage fluxes in secondly core due to asymmetric core structures. This large leakage inductance affects a drive circuit using a series-parallel combined resonant circuit, and the resonant characteristics in the drive circuit become very steep. In this state, the resonance circuit does not realize the desired function when the drive frequency fluctuates or the error of resonance parameters occurs. Therefore, this paper proposes a novel leakage flux cancellation technique used for ultrasonic spindle drive. The effectiveness of the proposed method is discussed from the theoretical analysis and experimental test..
38. Ryo Ute, Kazuya Fujiwara, Jun Imaoka, Masahito Shoyama, Limit Operating Frequency of Peak Current-Mode Control DC-DC Converter Considering Turn-Off Delay Time, 8th International Power Electronics Conference, IPEC-Niigata - ECCE Asia 2018 2018 International Power Electronics Conference, IPEC-Niigata - ECCE Asia 2018, 10.23919/IPEC.2018.8507512, 3773-3779, 2018.10, The aim of this paper is to present the mechanism of the frequency dividing operation and the limit operating frequency in the peak current-mode control DC-DC converter considering the turn-off delay time. The peak current mode control has the higher stability and the responsiveness than the conventional voltage mode control. However, if the switching frequency is increased ignoring the turn-off delay time, it would become the frequency dividing operation that the switching frequency operates lower than the clock frequency at the certain frequency. In this operation, there is a problem that the switching loss increases and the high frequency switching drive is hindered. In this paper, we clarified the mechanism of the dividing frequency operation and derived the relationship between the turn-off delay time and the limit operating frequency. Also, we derived the relationship when the slope compensation is applied as well. As experimental results, when there is the turn-off delay time, it was confirmed that the limit operating frequency of the DC-DC converter was limited to lower as the duty ratio was lower and the slope ratio of the slope compensation is close to 1.0..
39. Jun Imaoka, Kenkichiro Okamoto, Masahito Shoyama, Yuki Ishikura, Mostafa Noah, Masayoshi Yamamoto, Modeling, Magnetic Design, and Simulation Methods Considering DC Superimposition Characteristic of Powder Cores Used in Power Converters, 8th International Power Electronics Conference, IPEC-Niigata - ECCE Asia 2018 2018 International Power Electronics Conference, IPEC-Niigata - ECCE Asia 2018, 10.23919/IPEC.2018.8507874, 1095-1102, 2018.10, Powder cores have been gained much attention as one of the attractive magnetic cores used in power converters due to their superior features such as high saturation flux density or distributed air gaps. However, powder cores have a unique feature that the relative permeability of the magnetic core varies depending on the magnetic field intensity. However, modeling the variable relative permeability, the design method for powder cores, and computer simulation methods of non-linear inductance are well not discussed in the related literature. Therefore, this paper proposes a novel modeling, magnetic design methods, and simulation technique considering dc superimposition characteristics of powder cores. The modeling method uses a novel model equation representing the behavior of relative permeability under the dc current superimposition condition, which is helpful to evaluate the performance of powder cores and to properly design various magnetic components. Theoretical analysis has been presented and the effectiveness and the validity of the proposed methods are evaluated through simulation and experimental tests..
40. Mahmoud A. Gaafar, Gamal M. Dousoky, Emad M. Ahmed, Masahito Shoyama, Mohamed Orabi, New design approach for grid-current-based active damping of LCL filter resonance in grid-connected converters, Journal of Power Electronics, 10.6113/JPE.2018.18.4.1165, 18, 4, 1165-1177, 2018.07, This paper investigates the active damping of grid-connected LCL filter resonance using high-pass filter (HPF) of the grid current. An expression for such HPF is derived in terms of the filter components. This expression facilitates a general study of the actively damped filter behavior in the discrete time domain. Limits for the HPF parameters are derived to avoid the excitation of unstable open loop poles since such excitation can reduce both the damping performance and the system robustness. Based on this study, straightforward co-design steps for the active damping loop along with the fundamental current regulator are proposed. A numerical example along with simulation and experimental results are presented to verify the theoretical analyses..
41. Jun Imaoka, Kenkichiro Okamoto, Shota Kimura, Mostafa Noah, Wilmar Martinez, Masayoshi Yamamoto, Masahito Shoyama, A Magnetic Design Method Considering DC-Biased Magnetization for Integrated Magnetic Components Used in Multiphase Boost Converters, IEEE Transactions on Power Electronics, vol.33, iss.4, pp.3346-3362, 2018.04.
42. Mokhtar Aly, Emad M. Ahmed, Mohamed Orabi, Masahito Shoyama, An enhanced PWM method for loss balancing of five level T-type inverter in PV systems, 33rd Annual IEEE Applied Power Electronics Conference and Exposition (APEC) 2018, pp.2530-2535, 2018.03.
43. Mokhtar Aly, Emad M. Ahmed, Masahito Shoyama, Thermal stresses relief carrier-based PWM strategy for single-phase multilevel inverters, IEEE Transactions on Power Electronics, vol.32, iss.12, pp.9376-9388, 2017.12.
44. Mokhtar Aly, Emad M. Ahmed, Masahito Shoyama, Thermal Stresses Relief Carrier-Based PWM Strategy for Single-Phase Multilevel Inverters, IEEE TRANSACTIONS ON POWER ELECTRONICS, 10.1109/TPEL.2017.2654490, 32, 12, 9376-9388, 2017.12, Enhancing power cycling capability of power semiconductor devices is highly demanded in order to increase the long-term reliability of multilevel inverters. Ageing of power switches and their cooling systems leads to their accelerated damage due to excess power losses and junction temperatures. Therefore, thermal stresses relief (TSR) is the most effective solution for lifetime extension of power semiconductor devices. This paper presents a new TSR carrier-based pulse width modulation (TSRPWM) strategy for extending the lifetime of semiconductor switches in single-phase multilevel inverters. The proposed strategy benefits the inherent redundancy among switching states in multilevel inverters to optimally relieve the thermally stressed device. The proposed algorithm maintains the inverter operation without increased stresses on healthy switches and without reduction of the output power ratings. In addition, the proposed algorithm preserves voltage balance of the dc-link capacitors. The proposed strategy is validated on a single-phase five-level T-type inverter system with considering different locations of thermal stresses detection. Experimental prototype of the selected case study is built to verify the results. Moreover, comparisons with the most featured strategies in literature are given in detail..
45. Mokhtar Aly, Emad M. Ahmed, Masahito Shoyama, An improved model predictive controller for highly reliable grid connected photovoltaic multilevel inverters, 39th IEEE International Telecommunications Energy Conference (INTELEC) 2017, pp.450-455, 2017.10.
46. Baihua Zhang, Qiang Lin, Jun Imaoka, Masahito Shoyama, Satoshi Tomioka, Eiji Takegami, Conducted noise prediction for zero-crossing issue in totem-pole bridgeless PFC converter, 39th IEEE International Telecommunications Energy Conference (INTELEC) 2017, pp.396-401, 2017.10.
47. Mokhtar Aly, Emad M. Ahmed, Masahito Shoyama, Developing new lifetime prolongation SVM algorithm for multilevel inverters with thermally aged power devices, IET Power Electronics, vol.10, iss.15, pp.2248-2256, 2017.10.
48. Jun Imaoka, Kenkichiro Okamoto, Masahito Shoyama, Mostafa Noah, Shota Kimura, Masayoshi Yamamoto, A high-Reliable magnetic design method for three-Phase coupled inductor used in interleaved multi-Phase boost converters, 9th Annual IEEE Energy Conversion Congress and Exposition (ECCE) 2017, pp.873-880, 2017.10.
49. Masahito Shoyama, Takuma Sagara, Yusuke Yamashita, Jun Imaoka, Yu Yonezawa, Yoshiyasu Nakashima, Derivation of transfer function of LLC current resonant converter using numerical calculation, 9th Annual IEEE Energy Conversion Congress and Exposition (ECCE) 2017, pp.3056-3062, 2017.10.
50. Mokhtar Aly, Emad M. Ahmed, M. Shoyama, Thermal and Reliability Assessment for Wind Energy Systems with DSTATCOM Functionality in Resilient Microgrids, IEEE Transactions on Sustainable Energy, Vol.8, No.3, pp.953-965, 2017.07.
51. Mokhtar Aly, Emad M. Ahmed, Masahito Shoyama, A new real-time perfect condition monitoring for high-power converters, 3rd IEEE International Future Energy Electronics Conference (IFEEC) - ECCE Asia 2017-, pp.1473-1477, 2017.06.
52. Jun Imaoka, Myoungsik Nam, Masahito Shoyama, Hideaki Fujita, Design of series-parallel combined resonant circuit with rotary transformer used for ultrasonic spindle drive, 3rd IEEE International Future Energy Electronics Conference (IFEEC) - ECCE Asia 2017-, pp.2244-2249, 2017.06.
53. Jun Imaoka, Kenkichiro Okamoto, Masahito Shoyama, Daigoro Ebisumoto, Shota Kimura, Mostafa Noah, Masayoshi Yamamoto, Magnetic design and experimental evaluation of Integrated Magnetic Components used in Interleaved Multi-phase DC/DC converter with Phase Drive Control, 3rd IEEE International Future Energy Electronics Conference (IFEEC) - ECCE Asia 2017-, pp.2192-2197, 2017.06.
54. Baihua Zhang, Jun Imaoka, Masahito Shoyama, Satoshi Tomioka, Eiji Takegami, Study on zero-crossing conducted noise issue of totem-pole bridgeless PFC converter, 3rd IEEE International Future Energy Electronics Conference (IFEEC) - ECCE Asia 2017-, pp.2233-2237, 2017.06.
55. Mahmoud A. Gaafar, Gamal M. Dousoky, Emad M. Ahmed, M. Shoyama, Systematic Design of Grid-Current-Based Active Damping for Grid-Connected LCL Filters, IEEE APEC 2017, pp.2652-2657, 2017.03.
56. Gamal M. Dousoky, M. Shoyama, New Parameter for Current-Sensorless MPPT in Grid-Connected Photovoltaic VSIs, Solar Energy Journal (Elsevier), Vol.143, pp.113-119, 2017.02.
57. Gamal M. Dousoky, Masahito Shoyama, New parameter for current-sensorless MPPT in grid-connected photovoltaic VSIs, SOLAR ENERGY, 10.1016/j.solener.016.12.047, 143, 113-119, 2017.02, This paper a new quantity for current-sensorless power-angle-based MPPT for single-stage grid connected photovoltaic voltage-source inverters (VSIs). The proposed tracker eliminates the use of the current sensor by using only the voltage sensor: The current sensor is substituted with a new quantity, which is the sine value of the power-angle (the phase angle between the inverter output voltage and the power grid voltage). A theoretical proof for this quantity is developed and is provided. Then the controller is designed and implemented using a digital signal processor (DSP). Algorithms are configured on a fixed point DSP TMS320F2812. Moreover, a breadboard has been built-up for testing the use of the proposed tracker with a single-stage grid-connected photovoltaic voltage-source inverter. Both of simulation and experimental results show that the proposed tracker attains a satisfactory performance. On the other hand, it requires a good control tool to accurately achieve the arithmetic calculations. A substantial part of the manufacturing cost and complexity burdens of MPPTs involves the use of current sensors. Considering this investigation saves cost, decreases complexity, and therefore increases the power density of the MPPTs. (C) 2016 Elsevier Ltd. All rights reserved..
58. Gamal M. Dousoky, M. Shoyama, An AC MPPT with Active/Reactive Power Control Feature for Single-Stage Three-Phase Grid-Connected Photovoltaic VSIs, Electric Power Components & Systems Journal (Taylor & Francis), Vol.45, No.4, pp.442-450, 2017.01.
59. Mokhtar Aly, Gamal M. Dousoky, M. Shoyama, An Overheating-Tolerant Space Vector Modulation Algorithm for Multilevel Inverters, IEEJ Transactions on Electrical and Electronic Engineering, 10.1002/tee.22338, Vol.11, No. 2, pp. 75-S83, 2016.12.
60. T. Ota, Jun Imaoka, M. Shoyama, H. Onishi, S. Nagaoka, S. Morishita, Analysis and Design Method of ZCS DC-DC Converter in Consideration of the Parasitic Capacitance of Switch and Its Effect on Loss Reduction, IEEE 2nd Southern Power Electronics Conference (SPEC), No.297, 2016.12.
61. Jun Imaoka, K. Okamoto, D. Ebisumoto, S. Kimura, M. Yamamoto, M. Shoyama, A Novel Design Method of Integrated Magnetic Components Used in Two-phase Interleaved Converter with Phase Drive Control, The 3rd Symposium on Semiconductor Power Conversion (S2PC), pp.52-53, 2016.10.
62. Donny Radianto,M. Shoyama, Improved Incremental Conductance Based Maximum Power Point Tracking of Photovoltaic System, International Journal on Energy Conversion (I.R.E.CON.), Vol.4, No.5, pp.139-143, 2016.09.
63. Mokhtar Aly, Gamal M. Dousoky, Emad M. Ahmed, M. Shoyama, A Unified SVM Algorithm for Lifetime Prolongation of Thermally-Overheated Power Devices in Multi-Level Inverters, IEEE ECCE 2016 (Energy Conversion Congress and Exposition), S24-1, pp.1-6, 2016.09.
64. Mahmoud A. Gaafar, M. Shoyama, Design and Analysis of Observer-Based Active Damping for LCL Filter Resonance, システム情報科学府紀要, Vol.21, No.2, pp.39-44, 2016.07.
65. Mahmoud A. Gaafar, Emad M. Ahmed, M. Shoyama, A Two State Feedback Active Damping Strategy for the LCL Filter Resonance in Grid-Connected Converters, Journal of Power Electronics (JPE), Vol.16, No.4, pp.1587-1597, 2016.07.
66. Mahmoud A. Gaafar, Emad M. Ahmed, Masahito Shoyama, A Two State Feedback Active Damping Strategy for the LCL Filter Resonance in Grid-Connected Converters, JOURNAL OF POWER ELECTRONICS, 10.6113/JPE.2016.16.4.1587, 16, 4, 1587-1597, 2016.07, A novel active damping strategy for the LCL filter resonance is proposed using the grid current and the capacitor voltage. The proposed technique is deduced in the continuous time domain and a discussion for its discrete implementation is presented. According to the proposed technique, instability of the open loop system, which results in non-minimum phase behavior, can be avoided over wide range of resonant frequencies. Moreover, straightforward co-design steps for both the fundamental current regulator and the active damping loops can be used. A numerical example along with experimental results are introduced to validate the proposed strategy performance over wide range of resonant frequencies..
67. Baihua Zhang, Qiang Lin, Y. Shimada, Jun Imaoka, M. Shoyama, S. Tomioka, Analysis and Reduction Method of Conducted Noise in GaN HEMTs based Totem-pole Bridgeless PFC Converter, IEEE 8th IPEMC 2016-ECCE Asia, Mb1-07, 2016.05.
68. Mitsuru Sato, Reo Takiguchi, Jun Imaoka, M. Shoyama, A Novel Secondary PWM-Controlled interleaved LLC Resonant Converter for Load Current Sharing, IEEE 8th IPEMC 2016-ECCE Asia, P207, 2016.05.
69. Mahmoud A. Gaafar,Gamal M. Dousoky,M. Shoyama, New Active Damping Method for LCL Filter Resonance Based on Two Feedback System, IEEE APEC 2016, pp.2735-2741, 2016.03.
70. Donny Radianto,Gamal M. Dousoky,M. Shoyama, Design and Implementation of Fast PWM Boost Converter Based on Low Cost Microcontroller for Photovoltaic Systems, IEEE IECON 2015 (The 41st Annual Conference of the IEEE Industrial Electronics Society), pp.2325-2328, 2015.11.
71. Mokhtar Aly,Gamal M. Dousoky,M. Shoyama, Lifetime-Oriented SVPWM for Thermally-Overloaded Power Devices in Three-Level lnverters, IEEE IECON 2015 (The 42st Annual Conference of the IEEE Industrial Electronics Society), pp.3614-3619, 2015.11.
72. Mahmoud A. Gaafar,Gamal M. Dousoky,M. Shoyama, Dual Feedback Active Damping Method for Grid-Connected LCL Filter Resonance, IEEE IECON 2015 (The 43st Annual Conference of the IEEE Industrial Electronics Society), pp.3821-3826, 2015.11.
73. Mokhtar Aly,Gamal M. Dousoky,M. Shoyama, Reliability Enhancement of Multilevel Inverters through SVPWM-Based Thermal Management Methodology, IEEE IFEEC 2015 (2nd International Future Energy Electronics Conference), 10.1109/IFEEC.2015.7361605 , DC1, No.290469, 2015.11.
74. S. Ida,Gamal M. Dousoky,M. Shoyama,T. Yamashita, Performance Evaluation of Surge Energy Regenerative Two-Switch Power Supply with TEC values, IEEE IFEEC 2015 (2nd International Future Energy Electronics Conference), 10.1109/IFEEC.2015.7361444 , PE6, No.290182, 2015.11.
75. Donny Radianto,M. Shoyama, ANFIS Based Maximum Power Point Tracking Method for Photovoltaic System Using a Two-Phase Interleaved Boost Converter, International Review of Automatic Control (IREACO), Vol.8, No.6, pp.418-424, 2015.11.
76. Donny Radianto,Gamal M. Dousoky,M. Shoyama, MPPT Based on Incremental Conductance-Fuzzy Logic Algorithm for PhotovoItaic System under Variable Climate Conditions, IEEE INTELEC 2015 (37th International Telecommunications Energy Conference), TS31-1, pp.728-732, 2015.10.
77. Mokhtar Aly,Gamal M. Dousoky,M. Shoyama, Design and Validation of SVPWM Algorithm for Thermal Protection of T-Type Three-Level Inverters, IEEE INTELEC 2015 (37th International Telecommunications Energy Conference), PS08-39, pp.1074-1079, 2015.10.
78. Mahmoud A. Gaafar,Gamal M. Dousoky,M. Shoyama, Robustness Analysis for Observer Based Active Damping of LCL Filter at Different Resonant Frequencies, IEEE INTELEC 2015 (37th International Telecommunications Energy Conference), TS07-2, pp.173-178, 2015.10.
79. M. Sato,Gamal M. Dousoky,M. Shoyama, Improved Digital Control Scheme of Synchronous Rectification for Resonant Converter at Light Load Conditions, IEEE INTELEC 2015 (37th International Telecommunications Energy Conference), TS19-5, pp.457-461, 2015.10.
80. T. Takahashi,M. Miyamoto,Gamal M. Dousoky,M. Shoyama, Droop Control for Bi-Directional DC-DC Converters Used in Multi-Level Virtual Conductors, IEEE INTELEC 2015 (37th International Telecommunications Energy Conference), TS25-2, pp.600-605, 2015.10.
81. B. Zhang,K. Shi,Q. Lin,Gamal M. Dousoky,M. Shoyama,S. Tomioka, Conducted Noise Reduction of Totem-pole Bridgeless PFC Converter Using GaN HEMTs, IEEE INTELEC 2015 (37th International Telecommunications Energy Conference), TS13-2, pp.320-324, 2015.10.
82. Yuki Inoue, Yafei Gao, Masahito Shoyama, Hideaki Fujita, Application of Wireless Electromagnetic Resonance Technology to Rotary Transformer Used in Ultrasonic Spindle, 9th International Conference on Power Electronics (ICPE) - ECCE Asia, ThE2-1, 2015.06.
83. Hegazy Rezk Ahmed Hussien, Masahito Shoyama, Techno-economic Optimum Sizing of Stand-alone Photovoltaic/Fuel Cell Renewable System for Irrigation Water Pumping Applications, IEEE PECON 2014 (International Conference on Power & Energy), 3A-4, 2014.12.
84. Mokhtar Aly, Masahito Shoyama, An Efficient Neutral Point Voltage Control Algorithm with Reduced Switching Losses for Three Level Inverters, IEEE PECON 2014 (International Conference on Power & Energy), 4C-3, 2014.12.
85. Kewei Shi, Masahito Shoyama, Satoshi Tomioka, Common Mode Noise Reduction in Totem-pole Bridgeless PFC Converter, IEEE PEAC 2014 (International Power Electronics and Application Conference and Exposition ), pp.705-709, 2014.11.
86. Donny Radianto, Masahito Shoyama, Neural Network Based a Two Phase Interleaved Boost Converter for Photovoltaic System, ICRERA 2014 (3rd International Conference on Renewable Energy Research and Applications), No.148, 2014.10.
87. Mahmoud A. Gaafar, Masahito Shoyama, Active Damping for Grid-Connected LCL Filter based on Optimum Controller Design using Injected Grid Current Feedback Only, IEEE ECCE 2014 (Energy Conversion Congress and Exposition), pp.3628-3633, 2014.09.
88. Husam A. Ramadan, Masahito Shoyama, A Unified Model for the Multi-level Virtual Conductor, IEEE INTELEC 2014 (36th International Telecommunications Energy Conference), PO-27, 2014.09.
89. Mahmoud A. Gaafar, Masahito Shoyama, Active Damping for Grid-Connected LCL Filter Based on Optimum P+R Controller Design Using Injected Grid Current Feedback Only, IEEE INTELEC 2014 (36th International Telecommunications Energy Conference), PO-34, 2014.09.
90. Husam A. Ramadan, Yasutaka Imamura, Sihun Yang, Masahito Shoyama, Stability Considerations for DC Power Systems with Multi-level Virtual Conductors, システム情報科学府紀要, Vol.19, No.2, pp.41-46, 2014.09.
91. Husam A. Ramadan, Yasutaka Imamura, Sihun Yang, Masahito Shoyama, Performance of a Virtual Conductor in Dc Power Systems Using a Controlled Bidirectional DC-DC Converter, International Journal of Innovative Research in Electrical, Electronics, Instrumentation and Control Engineering, Vol. 2, Issue 9, pp.2002-2008, 2014.09.
92. Husam A. Ramadan, Yasutaka Imamura, Sihun Yang, Masahito Shoyama, A Unified Dynamic Model for Bi-directional DC-DC Converter, International Journal of Enhanced Research in Science Technology & Engineering, Vol.3, Issue 9, pp.228-238, 2014.09.
93. Donny Radianto, Masahito Shoyama, Anfis Based A Two-Phase Interleaved Boost Converter For Photovoltaic System, IEEE INTECH 2014 (4th International Conference on the Innovative Computing Technology), pp.19-24, 2014.08.
94. Husam A. Ramadan, Yasutaka Imamura, Sihun Yang, Masahito Shoyama, A New Stability Assessment Criterion for DC Power Systems Using Multi-level Virtual Conductors, IEEE COMPEL 2014 (15th IEEE Workshop on Control and Modeling for Power Electronics), pp.1-5, 2014.06.
95. Xiaochen Zhang, Masahito Shoyama, Common-Mode Noise Reduction with Two Symmetrical Three-Phase Inverters, IEICE 2014 International Symposium on Electromagnetic Compatibility, EMC’14/Tokyo, 13A1-A4, pp.61-64, 2014.05.
96. Kewei Shi, Masahito Shoyama, Satoshi Tomioka, A Study of Common Mode Noise Current of Bridgeless PFC Circuit Considering Voltage Change in Y-Capacitors, IEICE 2014 International Symposium on Electromagnetic Compatibility, EMC’14/Tokyo, 13A2-A3, pp.73-76, 2014.05.
97. Husam A. Ramadan, Yasutaka Imamura, Konosuke Kawachi, Sihun Yang, Masahito Shoyama, A Multi-Level Virtual Conductor as a Backbone of a DC Power Routing System, 2014 International Power Electronics Conference, IPEC-Hiroshima 2014 -ECCE Asia-, pp.863-867, 2014.05.
98. Haruomi Takashita, Masahito Shoyama, Yu Yonezawa, Yoshiyasu Nakashima, Efficiency Improvement of Power Supply with Transient Current Circuit Using Digital Control, 2014 International Power Electronics Conference, IPEC-Hiroshima 2014 -ECCE Asia-, pp.3386-3391, 2014.05.
99. Gamal M. Dousoky, Masahito Shoyama, Haitham Abu‐Rub, Dual-Mode Controller for MPPT in Single-Stage Grid-Connected Photovoltaic Inverters, IEEE IECON 2013 (The 39th Annual Conference of the IEEE Industrial Electronics Society), pp.663-668, 2013.11.
100. Gamal M. Dousoky, Masahito Shoyama, DSP-Based Simple and Efficient Synchronizer for Three-Phase Grid-Connected Renewable Energy Systems, IEEE IFEEC 2013 (1st International Future Energy Electronics Conference), pp.411-415, 2013.11.
101. Husam A. Ramadan, Yasutaka Imamura, Konosuke Kawachi, Sihun Yang, Masahito Shoyama, Multi-level Virtual Conductor Using Bidirectional DC-DC Converters, IEEE INTELEC 2013 (35th International Telecommunications Energy Conference), pp.2757-2763, 2013.10.
102. Gamal M. Dousoky, Masahito Shoyama, Current-Sensorless Power-Angle-Based MPPT for Single-Stage Grid-Connected Photovoltaic, IEEE ECCE 2013 (Energy Conversion Congress and Exposition), pp.105-109, 2013.09.
103. Emad M. Ahmed, Mohamed Orabi, Shoyama Masahito, High Efficient Variable step Size Incremental Resistance Maximum Power Point Tracker for PV, IEEE ECCE 2013 (Energy Conversion Congress and Exposition), pp.2435-2439, 2013.09.
104. Yasutaka Imamura, Husam A. Ramadan, Sihun Yang, Gamal M. Dousoky, Masahito Shoyama, Seamless Dynamic Model for DC-DC Converters Applicable to Bi-directional Power Transfer, EPE 2013 ECCE Europe (the 15th European Conference on Power Electronics and Applications), pp.1-10, 2013.09.
105. Yusuke Kawamura, Masahito Shoyama, Wireless Power Transmission Using LC Cancellation, 2013 IEEE ECCE ASIA DownUnder, June 2013, No. 10-3-2, pp. 1041-1045, 2013.06.
106. Seiya Abe, Toshiyuki Zaitsu, Junichi Yamamoto, Shinji Ueda, Sihun Yang, Masahito Shoyama, Tamotsu Ninomiya, Consideration of Current Resonant Converter Topology for Bi-Directional Applications, The 10th IEEE International Conference on Power Electronics and Drive Systems (PEDS 2013), A2L-A.2, pp.153-158, 2013.04.
107. Kiyoshi Masumoto, Kewei Shi, Masahito Shoyama, Satoshi Tomioka, Comparative Study on Efficiency and Switching Noise of Bridgeless PFC Circuits, The 10th IEEE International Conference on Power Electronics and Drive Systems (PEDS 2013), B3P-L.8, pp.613-618, 2013.04.
108. Yasutaka Imamura, Husam A. Ramadan, Sihun Yang, Gamal M. Dousoky, Masahito Shoyama, Seamless Dynamic Model for Bi-Directional DC-DC Converter, The 10th IEEE International Conference on Power Electronics and Drive Systems (PEDS 2013), B4L-F.3, pp.1109-1113, 2013.04.
109. Seiya Abe, Sihun Yang, Masahito Shoyama, Yoichi Ishizuka, Tamotsu Ninomiya, Masato Kaga, Prototype Evaluation of Over 10W/cm^3 High Power Density Converter for 400VDC Power Distribution System in Data Center, The 10th IEEE International Conference on Power Electronics and Drive Systems (PEDS 2013), C2L-A.3, pp.1280-1284, 2013.04.
110. Seiya Abe, Toshiyuki Zaitsu, Junichi Yamamoto, Shinji Ueda, Sihun Yang, Masahito Shoyama, Tamotsu Ninomiya, Adaptive Driving of Synchronous Rectifier for LLC Converter Without Signal Sensing, IEEE APEC 2013, pp.1370-1375, 2013.03.
111. Gamal M. Dousoky, Masahito Shoyama, Development of Eco-friendly Photovoltaic Energy Systems Through "Energy Efficiency" Technology - A Roadmap and an Application in Egypt and Japan, ICEST2013, pp.79-90, 2013.02.
112. Gamal M. Dousoky, Emad M. Ahmed, Masahito Shoyama, MPPT Schemes for Single-Stage Three-Phase Grid-Connected Photovoltaic Voltage-Source Inverters, ICIT 2012, pp.600-605, 2013.02.
113. Sihun Yang, Seiya Abe, Toshiyuki Zaitsu, Junichi Yamamoto, Masahito Shoyama, Tamotsu Ninomiya, Consideration of Operating Characteristics for Bi-directional LLC Resonant Converter, International Journal of Renewable Energy Research, Vol.2, No.4, pp.790-796, 2013.01.
114. Kiyoshi Masumoto, Masahito Shoyama, Comparative Study about Efficiency and Switching Noise of Bridgeless PFC Circuits, ICRERA 2012, 2012.11.
115. Sihun Yang, Seiya Abe, Toshiyuki Zaitsu, Junichi Yamamoto, Masahito Shoyama, Tamotsu Ninomiya, Detail Operating Characteristics of Bi-directional LLC Resonant Converter, ICRERA 2012, 2012.11.
116. Seiya Abe, Toshiyuki Zaitsu, Junichi Yamamoto, Sihun Yang, Masahito Shoyama, Tamotsu Ninomiya, AC Analysis of Symmetry and Asymmetry Bi-directional Current Resonant Converter, ICRERA 2012, 2012.11.
117. Sihun Yang, Kenta Goto, Yasutaka Imamura, Masahito Shoyama, Dynamic Characteristics Model of Bi-Directional DC-DC Converter Using State-Space Averaging Method, IEEE INTELEC 2012, Program #19.2, 2012.10.
118. Seiya Abe, Toshiyuki Zaitsu, Junichi Yamamoto, Shinji Ueda, Sihun Yang, Masahito Shoyama, Tamotsu Ninomiya, Operating Characteristics of Push-Pull Type Series Resonant DC-DC Converter with Synchronous Rectifier, IEEE INTELEC 2012, Program #1.4, 2012.10.
119. Seiya Abe, Toshiyuki Zaitsu, Junichi Yamamoto, Shinji Ueda, Sihun Yang, Masahito Shoyama, Tamotsu Ninomiya, Sensing-Less Drive of Synchronous Rectifier for LLC Resonant Converter, IEEE INTELEC 2012, Program #22.2, 2012.10.
120. Sihun Yang, Seiya Abe, Masahito Shoyama, Design consideration of Low-Profile LLC Resonant Converter for Reducing Temperature of The Transformer, システム情報科学府紀要, Vol.17, No.2, pp.49-54, 2012.09.
121. Gamal M. Dousoky, Emad M. Ahmed, Masahito Shoyama, Current-Sensorless MPPT with DC-DC Boost Converter for Photovoltaic Battery Chargers, IEEE ECCE 2012, pp.1607-1614, 2012.09.
122. Gamal M. Dousoky, Abou-Hashema M. El-Sayed, Masahito Shoyama, Increasing Energy-Efficiency in Solar Radiation Trackers for Photovoltaic Arrays, IEEE ECCE 2012, pp.4113-4120, 2012.09.
123. Seiya ABE, Sihun YANG, Masahito Shoyama, Tamotsu NINOMIYA, Akira MATSUMOTO, Akiyoshi FUKUI, Malfuntion Issue of SiC-SIT Based DC Circuit Breaker in 400V DC Power Distribution Systems for Data Centers, IEICE Trans. on Commun., Vol.E95-B, No.6, pp.1990-1996, 2012.06.
124. Gamal M. Dousoky, Emad M. Ahmed, Masahito Shoyama, An Adaptive Frequency Hopping Technique for Conducted-Noise Reduction in DC-DC Converters, IEEE 7th IPEMC 2012-ECCE Asia, pp.1761-1765, 2012.06.
125. Emad M. Ahmed, Gamal M. Dousoky, Masahito Shoyama, On the Behaviour of Marine and Tidal Current Converters with DC-DC Boost Converter, IEEE 7th IPEMC 2012-ECCE Asia, pp.2250-2254, 2012.06.
126. Seiya Abe, Sihun Yang, Masahito Shoyama, Tamotsu Ninomiya, Akira Matsumoto, Akiyoshi Fukui, Malfunction Issue of SiC-SIT Based DC Circuit Breaker in 400 V DC Power Distribution Systems for Data Centers, IEICE TRANSACTIONS ON COMMUNICATIONS, 10.1587/transcom.E95.B.1990, E95B, 6, 1990-1996, 2012.06, 400 V DC power distribution systems for data centers require a fast response DC circuit breaker is required. The semiconductor DC circuit breaker is an important key technology in DC power distribution systems. This paper considers the malfunction of Silicon Carbide-Static. Induction Transistor (SiC-SIT) based DC circuit breakers in 400V DC power distribution systems for data centers. The malfunction mechanism is explained, and a solution is proposed. Investigations are achieved by MATLAB/Simulink and experimental verification..
127. Emad M. Ahmed, Masahito Shoyama, Enhancing the Performance of the Marine and Tidal Current Converters Using DC-DC Boost Converter, Journal of Energy and Power Engineering, Vol. 6, No. 3, pp. 478-484, Mar. 2012, 2012.03.
128. Seiya Abe, Sihun Yang, Masahito Shoyama, Tamotsu Ninomiya, Akira Matsumoto, Akiyoshi Fukui, Operating Mechanism of SiC-SIT DC Circuit Breaker in 400V-DC Power Supply System for Data Center --In Case of Grounding Fault--, IEEE APEC 2012, pp.2189-2194, Feb. 2011, 2012.02.
129. Emad M. Ahmed, Masahito Shoyama, Scaling Factor Design Based Variable Step Size Incremental Resistance Maximum Power Point Tracking for PV Systems, Journal of Power Electronics (JPE), Vol.12, No.1, pp.164-171, 2012.01.
130. Emad M. Ahmed, Masahito Shoyama, Scaling Factor Design Issues in Variable Step Size Incremental Resistance MPPT in PV systems, 9th International Conference on Power Electronics and Drive Systems (PEDS 2011), Dec. 2011, pp.889-894, 2011.12.
131. Seiya Abe, Sihun Yang, Masahito Shoyama, Tamotsu Ninomiya, Akira Matsumoto, Akiyoshi Fukui, Malfunction Analysis of SiC-SIT DC Circuit Breaker in 400V-DC Power Supply System, 9th International Conference on Power Electronics and Drive Systems (PEDS 2011), Dec. 2011, pp.109-114, 2011.12.
132. Emad M. Ahmed, Masahito Shoyama, Novel Stability Analysis of Variable Step Size Incremental Resistance INR MPPT for PV systems, IEEE International Conf. on Industrial Electronics, Control and Instrumentation (IECON 2011), Nov. 2011, pp. 3761-3766, 2011.11.
133. Gamal M. Dousoky, Abou-Hashema M. El-Sayed, Masahito Shoyama, Improved Orientation Strategy for Energy-Efficiency in Photovoltaic Panels, Journal of Power Electronics (JPE), Vol.11, No.3, pp. 335-341, May 2011, 2011.05.
134. Emad M. Ahmed, Masahito Shoyama, New Single Current Sensor Based Variable Step Size MPPT for Stand-alone Battery Storage PV Systems, PCIM 2010 (in Nurnberg, Germany), pp.381-387, May 2011, 2011.05.
135. Emad M. Ahmed, Masahito Shoyama, Stability Study of Variable Step Size Incremental Conductance/Impedance MPPT for PV systems, 8th International Conference on Power Electronics (ICPE 2011) - ECCE Asia, May-Jun. 2011, TuB2-3, 2011.05.
136. Sihun Yang, Seiya Abe, Masahito Shoyama, Design Consideration of Two Flat Transformers in a Low-Profile LLC Resonant Converter, 8th International Conference on Power Electronics (ICPE 2011) - ECCE Asia, May-Jun. 2011, WeA2-3, 2011.05.
137. Gamal M. Dousoky, Abou-Hashema M. El-Sayed, Masahito Shoyama, Maximizing Energy-Efficiency in Single-Axis Solar Trackers for Photovoltaic Panels, 8th International Conference on Power Electronics (ICPE 2011) - ECCE Asia, May-Jun. 2011, ThF1-1, 2011.05.
138. Emad M. Ahmed, Masahito Shoyama, Variable Step Size Maximum Power Point Tracker Using a Single Variable for Stand-alone Battery Storage PV Systems, IEEE ICIT-SSST 2011 (in Auburn,Alabama, USA; Electronic Presentation), Mar. 2011, 2011.03.
139. Emad M. Ahmed, Masahito Shoyama, Variable Step Size Maximum Power Point Tracker Using Single Variable for Stand-alone Battery Storage PV Systems, Journal of Power Electronics (JPE), Vol.11, No.2, pp. 218-227, Mar. 2011, 2011.03.
140. Seiya Abe, Sihun Yang, Mariko Ogawa, Masahito Shoyama, Tamotsu Ninomiya, Akira Matsumoto, Akiyoshi Fukui, Malfunction Issue of SiC-SIT DC Circuit Breaker in HVDC Power Supply System, IEEE APEC 2011, D10.16, Mar. 2011, 2011.03.
141. Emad M. Ahmed, Masahito Shoyama, Variable Step Size Maximum Power Point Tracker Using a Single Variable for Stand-alone Battery Storage PV Systems, JOURNAL OF POWER ELECTRONICS, 11, 2, 218-227, 2011.03, The subject of variable step size maximum power point tracking (MPPT) algorithms has been addressed in the literature. However, most of the addressed algorithms tune the variable step size according to two variables: the photovoltaic (PV) array voltage (V-PV) and the PV array current (I-PV). Therefore, both the PV array current and voltage have to be measured. Recently, maximum power point trackers that are based on a single variable (I-PV or V-PV) have received a great deal of attention due to their simplicity and ease of implementation, when compared to other tracking techniques. In this paper, two methods have been proposed to design a variable step size MPPT algorithm using only a single current sensor for stand-alone battery storage PV systems. These methods utilize only the relationship between the PV array measured current and the converter duty cycle (D) to automatically adapt the step change in the duty cycle to reach the maximum power point (MPP) of the PV array. Detailed analyses and flowcharts of the proposed methods are included. Moreover, a comparison has been made between the proposed methods to investigate their performance in the transient and steady states. Finally, experimental results with field programmable gate arrays (FPGAs) are presented to verify the performance of the proposed methods..
142. Gamal M. Dousoky, Masahito Shoyama, Tamotsu Ninomiya, FPGA-Based Spread-Spectrum Schemes for Conducted-Noise Mitigation in DC-DC Power Converters: Design, Implementation,, Experimental Investigation, IEEE Transactions on Industrial Electronics, pp.429 - 435, Feb. 2011, 2011.02.
143. Gamal M. Dousoky, Masahito Shoyama, Tamotsu Ninomiya, FPGA-Based Spread-Spectrum Schemes for Conducted-Noise Mitigation in DC-DC Power Converters: Design, Implementation, and Experimental Investigation, IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, 10.1109/TIE.2010.2049708, 58, 2, 429-435, 2011.02, This paper proposes a family of spread-spectrum schemes, several of which are new, for conducted-noise reduction in dc-dc converters. The schemes use three randomized parameters to generate the switching signals: carrier frequency, duty ratio, and pulse position. The increasing performance and cost reduction of field-programmable gate array (FPGA) technology have made the application of these schemes possible in this field. A theoretical framework for a general representative scheme is provided. Then, the proposed schemes are designed and implemented using an FPGA-based controller. Furthermore, the effect of using the proposed controller on common-mode, differential-mode, and total conducted-noise characteristics of the dc-dc converter is experimentally investigated. In addition, the three randomization parameters are swept to determine the values that best achieve the conducted-noise spectrum spread. All studied cases are designed, implemented, and experimentally investigated. Then, the conducted-noise spectra are compared. The experimental results show that the use of the proposed controller with the determined randomization values significantly improves the conducted-noise spectrum and effectively reduces the noise peaks at both high-and low-frequency ranges..
144. Seiya Abe, Mariko Ogawa, Toshiyuki Zaitsu, Satoshi Obata, Masahito Shoyama, Tamotsu Ninomiya, Investigation of Parameter Tolerance on Digitally Controlled DC-DC Converter with Pole-Zero-Cancellation Technique, IEEE APCCAS 2010, pp.476-479, Dec. 2010, 2010.12.
145. Sihun Yang, Seiya Abe, Masahito Shoyama, Design of Low-Profile LLC Resonant Converter for Low Transformer Loss, IEEE TENCON 2010, No.T1-18.4, pp.1301-1306, Nov. 2010, 2010.11.
146. Seiya Abe, Sihun Yang, Mariko Ogawa, Masahito Shoyama, Tamotsu Ninomiya, Akira Matsumoto, Akiyoshi Fukui, Mikio Yamasaki, Malfunction Suppression of Semiconductor Circuit Breaker in High Voltage DC Power Supply System, IEEE TENCON 2010, No.T1-17.3, pp.1278-1283, Nov. 2010, 2010.11.
147. Emad M. Ahmed, Masahito Shoyama, Modified Adaptive Variable Step-Size MPPT Based-on Single Current Sensor, IEEE TENCON 2010, No.T1-8.2, pp.1235-1240, Nov. 2010, 2010.11.
148. Seiya Abe, Mariko Ogawa, Toshiyuki Zaitsu, Satoshi Obata, Masahito Shoyama, Tamotsu Ninomiya, Dynamic Characteristics of Digitally Controled Conveter with Pole-Zero-Cancellation Techique, IEEE TENCON 2010, No.T1-2.3, pp.25-30, Nov. 2010, 2010.11.
149. Emad M. Ahmed, Masahito Shoyama, Highly Efficient Variable-Step-Size Maximum Power Point Tracker for PV Systems, IEEE ISEEE 2010, pp.112-117, Sep. 2010, 2010.09.
150. Seiya Abe, Kentaro Fukushima, Sihun Yang, Mariko Ogawa, Kosuke Nomura, Masahito Shoyama, Tamotsu Ninomiya, Akira Matsumoto, Akiyoshi Fukui, Mikio Yamasaki, Malfunction Mechanism of Semiconductor Circuit Breaker in HVDC Power Supply System, IEEE ECCE 2010, pp.3733-3738, Sep. 2010, 2010.09.
151. Gamal M. Dousoky, Masahito Shoyama, Tamotsu Ninomiya, On Factors Affecting EMI-Performance of Noise-Mitigating Digital Controllers in DC-DC Converters -- An Experimental Investigation, IEEE ECCE 2010, pp.1239-1245, Sep. 2010, 2010.09.
152. Sihun Yang, Seiya Abe, Masahito Shoyama, Parametric Analysis of LLC Resonant Converter Using Flat Transformer for Loss Reduction, EPE-PEMC 2010, pp.T2-(204-209), Sep. 2010, 2010.09.
153. Seiya Abe, Kentaro Fukushima, Sihun Yang, Mariko Ogawa, Kosuke Nomura, Masahito Shoyama, Tamotsu Ninomiya, Akira Matsumoto, Akiyoshi Fukui, Mikio Yamasaki, Consideration for the Malfunction of Semiconductor Circuit Breaker in High Voltage DC Power Supply System, EPE-PEMC 2010, pp.T6-(171-175), Sep. 2010, 2010.09.
154. Gamal M. Dousoky, Masahito Shoyama, Tamotsu Ninomiya, A Comparative Investigation of Several Frequency Modulation Profiles for Programmed Switching Controllers Targeted Conducted-Noise Reduction in DC-DC Converters, IEICE Trans. on Commun., Vol.E93-B, No.9, pp.2265-2272, Sep. 2010, 2010.09.
155. E. Firmansyah, S. Tomioka, S. Abe, M. Shoyama, T. Ninomiya, Totem-Pole Power-Factor-Correction Converter under Critical-Conduction-Mode Interleaved Operation, IEICE Trans. on Commun., Vol.E93-B, No.9, pp.2250-2256, Sep. 2010, 2010.09.
156. Gamal M. Dousoky, Masahito Shoyama, Tamotsu Ninomiya, A Comparative Investigation of Several Frequency Modulation Profiles for Programmed Switching Controllers Targeted Conducted-Noise Reduction in DC-DC Converters, IEICE TRANSACTIONS ON COMMUNICATIONS, 10.1587/transcom.E93.B.2265, E93B, 9, 2265-2272, 2010.09, This paper investigates the effect of several frequency modulation profiles on conducted-noise reduction in dc-dc converters with programmed switching controller. The converter is operated in variable frequency modulation regime. Twelve switching frequency modulation profiles have been studied. Some of the modulation data are prepared using MATLAB software, and others are generated online. Moreover, all the frequency profiles have been designed and implemented using FPGA and experimentally investigated. The experimental results show that the conducted-noise spreading depends on both the modulation sequence profile and the statistical characteristics of the sequence. A substantial part of the manufacturing cost of power converters for telecommunication applications involves designing filters to comply with the EMI limits. Considering this investigation significantly reduces the filter size..
157. Eka Firmansyah, Satoshi Tomioka, Seiya Abe, Masahito Shoyama, Tamotsu Ninomiya, Totem-Pole Power-Factor-Correction Converter under Critical-Conduction-Mode Interleaved Operation, IEICE TRANSACTIONS ON COMMUNICATIONS, 10.1587/transcom.E93.B.2250, E93B, 9, 2250-2256, 2010.09, This paper proposes a new power-factor-correction (PFC) topology, and explains its operation principle, its control mechanism, related application problems followed by experimental results. In this proposed topology, critical-conduction-mode (CRM) interleaved technique is applied to a bridgeless PFC in order to achieve high efficiency by combining benefits of each topology. This application is targeted toward low to middle power applications that normally employs continuous-conduction-mode boost converter..
158. Sihun Yang, Seiya Abe, Masahito Shoyama, Operating Temperature Reduction of Low-Profile Transformer in LLC Resonant Converter for PDP, IEEE ISIE 2010, Vol.10, No.4, pp.963-968, Jul. 2010, 2010.07.
159. Gamal M. Dousoky, Masahito Shoyama, Tamotsu Ninomiya, A Double-Hybrid Spread-Spectrum Technique for EMI Mitigation in DC-DC Switching Regulators, Journal of Power Electronics (JPE), Vol.10, No.4, pp.342-350, Jul. 2010, 2010.07.
160. Gamal M. Dousoky, Masahito Shoyama, Tamotsu Ninomiya, A Double-Hybrid Spread-Spectrum Technique for EMI Mitigation in DC-DC Switching Regulators, JOURNAL OF POWER ELECTRONICS, 10, 4, 342-350, 2010.07, Randomizing the switching frequency (RSF) to reduce the electromagnetic interference (EMI) of switching power converters is a well-known technique that has been previously discussed. The randomized pulse position (RPP) technique, in which the switching frequency is kept fixed while the pulse position (the delay from the starting of the switching cycle to the turn-on instant within the cycle) is randomized, has been previously addressed in the literature for the same purpose. This paper presents a double-hybrid technique (DHB) for EMI reduction in dc-dc switching regulators. The proposed technique employed both the RSF and the RPP techniques. To effectively spread the conducted-noise frequency spectrum and at the same time attain a satisfactory output voltage quality, two parameters (switching frequency and pulse position) were randomized, and a third parameter (the duty ratio) was controlled by a digital compensator. Implementation was achieved using field programmable gate array (FPGA) technology, which is increasingly being adopted in industrial electronic applications. To evaluate the contribution of the proposed DHB technique, investigations were carried out for each basic PWM, RPP, RSF, and DUB technique. Then a comparison was made of the performances achieved. The experimentally investigated features include the effect of each technique on the common-mode, differential-mode, and total conducted-noise characteristics, and their influence on the converter's output ripple voltage..
161. Seiya Abe, Kosuke Nomura, Kentaro Fukushima, Masahito Shoyama, Tamotsu Ninomiya, Akira Matsumoto, Akiyoshi Fukui, Mikio Yamasaki, Study on Malfunction Mechanism of Semiconductor Circuit Breaker in 400V DC Power Supply System, IPEC-Sapporo 2010, pp.2644-2649, Jun. 2010, 2010.06.
162. Gamal M. Dousoky, Masahito Shoyama, Consideration for Digital Controllers Targeted at Conducted-Noise Spectrum-Spreading in DC-DC Converters, IPEC-Sapporo 2010, pp.920-926, Jun. 2010, 2010.06.
163. Sihun Yang, Seiya Abe, Masahito Shoyama, Design Consideration of Flat Transformer in LLC Resonant Converter for Low Core Loss, IPEC-Sapporo 2010, pp.343-348, Jun. 2010, 2010.06.
164. Sihun Yang, Seiya Abe, Masahito Shoyama, Design Consideration of Reduction Flat Transformer Temperature in LLC Resonant Converter for Plasma Display, SPEEDAM 2010, pp.1141-1145, Jun. 2010, 2010.06.
165. Seiya Abe, Mariko Ogawa, Toshiyuki Zaitsu, Satoshi Obata, Masahito Shoyama, Tamotsu Ninomiya, Power-Stage Frequency Response Cancellation of DC-DC Converter with Digital Control, SPEEDAM 2010, pp.44-49, Jun. 2010, 2010.06.
166. Gamal M. Dousoky, Masahito Shoyama, Tamotsu Ninomiya, Conducted-Noise Characteristics of a Digitally-Controlled Randomly-Switched DC-DC Converter with an FPGA-Based Implementation, Journal of Power Electronics (JPE), Vol.10, No.3, pp.228-234, May. 2010, 2010.05.
167. Gamal M. Dousoky, Masahito Shoyama, FPGA-Based Digital Implementation of a Hybrid Spread-Spectrum Technique for EMI Mitigation in DC-DC Converters, PCIM 2010, pp.779-784, May. 2010, 2010.05.
168. Gamal M. Dousoky, Masahito Shoyama, Tamotsu Ninomiya, Conducted-Noise Characteristics of a Digitally-Controlled Randomly-Switched DC-DC Converter with an FPGA-Based Implementation, JOURNAL OF POWER ELECTRONICS, 10, 3, 228-234, 2010.05, This paper investigates the conducted-noise characteristics of a digitally-controlled randomly-switched dc-dc converter. In order to investigate the effect of the suggested digital controller on the conducted-noise characteristics of a dc-dc converter, three factors have been studied: the field-programmable gate array (FPGA) clock speed, the randomization ratio percentage, and the effect of using a closed loop feedback controller. A field-programmable gate array is much more flexible than analog control circuits, has a lower cost, and can be used for power supply applications. A novel FPGA-based implementation has been suggested for obtaining the experimental validations and realizing the studied concepts. Furthermore, the experimental results have been discussed and design guidelines have been included..
169. K. Fukushima, I. Norigoe, M. Shoyama, T. Ninomiya, Y. Harada, K. Tsukakoshi, Input current-ripple reduction on Pulse-link DC-AC converter for fuel cell applications operated by zero-current-slope mode, IEEE ICIT 2010, pp.1201-1205, Mar. 2010, 2010.03.
170. S. Abe, M. Ogawa, T. Zaitsu, S. Obata, M. Shoyama, T. Ninomiya, Dynamic characteristics improvement of digital controlled DC-DC converter by means of PZC control, IEEE ICIT 2010, pp.750-755, Mar. 2010, 2010.03.
171. Gamal M. Dousoky, Masahito Shoyama, Tamotsu Ninomiya, Triple-Hybrid Switching Strategy for Conducted-Noise Level Reduction in DC-DC Converters, Research Reports on ISEE of Kyushu University, Vol.15, No.1, pp.25-30, Mar. 2010, 2010.03.
172. E. Firmansyah, S. Tomioka, S. Abe, M. Shoyama, T. Ninomiya, An Interleaved Totem-Pole Power Factor Correction Converter, Research Reports on ISEE of Kyushu University, Vol.15, No.1, pp.19-24, Mar. 2010, 2010.03.
173. Kentaro Fukushima, Isami Norigoe, Masahito Shoyama, Tamotsu Ninomiya, Yosuke Harada, Kenta Tsukakoshi, Analysis of Pulse-link DC-AC Converter for Fuel Cells Applications Operated in Zero-Current-Slope Mode, IEEE APEC 2010, pp.289-294, Feb. 2010, 2010.02.
174. E. Firmansyah, S. Abe, M. Shoyama, S. Tomioka, An Active-Clamped Full-Wave Zero-Current-Switched Quasi-Resonant Boost Converter in Power Factor Correction Application, IEEE APEC 2010, pp.30-35, Feb. 2010, 2010.02.
175. Shinya HIROMITSU, Mariko OGAWA, Seiya ABE, Masahito SHOYAMA, Yu YONEZAWA, Naoyuki MISHIMA, Transient Current Circuit for Switching Loss Reduction in Buck Converters, INTELEC 2009, PC3-2, pp.1-5, Oct. 2009, 2009.10.
176. Seiya ABE, Mariko OGAWA, Toshiyuki ZAITSU, Satoshi OBATA, Masahito SHOYAMA, Tamotsu NINOMIYA, Frequency Response Improvement of DSP Controlled DC-DC Converter with Pole-Zero Cancellation Technique, INTELEC 2009, PC3-3, pp.1-6, Oct. 2009, 2009.10.
177. Seiya ABE, Kosuke NOMURA, Kentaro FUKUSHIMA, Masahito SHOYAMA, Tamotsu NINOMIYA, Akira MATSUMOTO, Akiyoshi FUKUI, Mikio YAMASAKI, Noise Current Characteristics of Semiconductor Circuit Breaker during Break-Off Condition in DC Power Supply System, INTELEC 2009, PA1-3, pp.1-5, Oct. 2009, 2009.10.
178. Kentaro FUKUSHIMA, Isami NORIGOE, Masahito SHOYAMA, Tamotsu. NINOMIYA, Yosuke HARADA, Kenta TSUKAKOSHI, The Effect of Series LC Circuit Parameters on Current-Ripple Reduction in Pulse-Link DC-AC Converter for Fuel Cell Applications, INTELEC 2009, RE4-1, pp.1-6, Oct. 2009, 2009.10.
179. EKA Firmansyah, Satoshi TOMIOKA, Seiya ABE, Masahito SHOYAMA, Tamotsu NINOMIYA, A Critical-Conduction-Mode Bridgeless Interleaved Boost Power Factor Correction, INTELEC 2009, PC16-2, pp.1-5, Oct. 2009, 2009.10.
180. G. M. Dousoky, M. Shoyama, T. Ninomiya, Double-Hybrid Spread-Spectrum Technique for Conducted-EMI Reduction in DC-DC Switching Regulators with FPGA-Based Controller, INTELEC 2009, PEC-2, pp.1-6, Oct. 2009, 2009.10.
181. Sihun Yang, Seiya Abe, Masahito Shoyama, Design of LLC Resonant Converter Using Planar Magnetic Component, INTELEC 2009, PC14-4, pp.1-5, Oct. 2009, 2009.10.
182. Seiya ABE, Masahito SHOYAMA, Tamotsu NINOMIYA, Optimal Design of Output Filter Capacitor for Peak Current Mode Control Converter with First-Order Response, EPE 2009, D.S.3-2, pp. 1-8, Sep. 2009, 2009.09.
183. G. M. Dousoky, M. Shoyama, T. Ninomiya, Triple-Hybrid Spread-Spectrum Technique for Conducted-Noise Reduction in DC-DC Converters with an FPGA-Based Implementation, EPE 2009, D.S.1-9, pp. 1-8, Sep. 2009, 2009.09.
184. EKA Firmansyah, Satoshi TOMIOKA, Seiya ABE, Masahito SHOYAMA, Tamotsu NINOMIYA, A Zero-Current-Switch Quasi-Resonant Boost Converter with Transformer Compensated Clamp Circuit, EPE 2009, D.S.1-1, pp. 1-8, Sep. 2009, 2009.09.
185. Kentaro FUKUSHIMA, Isami NORIGOE, Masahito SHOYAMA, Tamotsu. NINOMIYA, Yosuke HARADA, Kenta TSUKAKOSHI, Influence of Small-Series LC circuit on the Input Current-Ripple for Pulse-Link DC-AC Converter for Fuel Cells Applications, EPE 2009, L.S.1f, pp. 1-8, Sep. 2009, 2009.09.
186. G. M. Dousoky, M. Shoyama, T. Ninomiya, Studying the Design and Performance of Conducted-Noise Spectrum Spreading in DC-DC Converters with an FPGA-Based Controller, 2009 International Symposium on Electromagnetic Compatibility, EMC’09/Kyoto, 2009.07.
187. S. Abe, M. Hirokawa, M. Shoyama, T. Ninomiya, Optimal Design Considerations of a Bus Converter for On-Board Distributed Power Systems, Journal of Power Electronics (JPE), Vol.9, No.3, pp.447-455, 2009.05.
188. E. Firmansyah, S. Tomioka, S. Abe, M. Shoyama, T. Ninomiya, Steady State Characteristics of Active-Clamped Full-Wave Zero-Current-Switched Quasi-Resonant Boost Converters, IEEE 6th IPEMC 2009-ECCE Asia, pp. 556-560, 2009.05.
189. G. M. Dousoky, M. Shoyama, T. Ninomiya, FPGA-Based Techniques for Conducted-Noise Mitigation in DC-DC Power Converters, 2009 Korea-Japan Joint Conference on AP/EMC/EMT, KJJC’09, 2009.05.
190. E. Firmansyah, S. Tomioka, S. Abe, M. Shoyama, T. Ninomiya, Zero Current Switch-Quasi Resonant Boost Converter Performance in Power Factor Correction Application, IEEE APEC 2009, pp. 1165-1169, 2009.02.
191. K. Fukushima, I. Norigoe, M. Shoyama, T. Ninomiya, Y. Harada, K. Tsukakoshi, Input Current-Ripple Consideration for the Pulse-Link DC-AC Converter for Fuel Cells by Small Series LC Circuit, IEEE APEC 2009, pp. 447-451, 2009.02.
192. G. M. Dousoky, M. Shoyama, T. Ninomiya, A Novel Implementation of an FPGA-Based Controller for Conducted-Noise Reduction in Randomly Switched DC-DC Converters, IEEE APEC 2009, pp. 65-69, 2009.02.
193. G. M. Dousoky, M. Shoyama, T. Ninomiya, FPGA-Based Design and Implementation of Spread-Spectrum Schemes for Conducted-Noise Reduction in DC-DC Converters, ICIT 2009, AF-011282, 2009.02.
194. Characteristics of a Pulse-Link DC-AC Converter for Fuel Cells.
195. K. Fukushima, T. Ninomiya, M. Shoyama, I. Norigoe, Y. Harada, K. Tsukakoshi, Input Current-Ripple Reduction of a Pulse-link DC-AC Converter for Fuel Cells, INTELEC 2008, No. 29-3, 2008.09.
196. K. Fukushima, T. Ninomiya, M. Shoyama, I. Norigoe, Y. Harada, K. Tsukakoshi, Consideration for Input Current-Ripple of Pulse-link DC-AC Converter for Fuel Cells, EPE-PEMC 2008, pp. 148-153, 2008.09.
197. S. Abe, M. Hirokawa, M. Shoyama, T. Ninomiya, Optimal Bus Capacitance Design for System Stability in On-Board Distributed Power Architecture, EPE-PEMC 2008, pp. 401-407, 2008.09.
198. K. Fukushima, T. Ninomiya, M. Shoyama, I. Norigoe, Y. Harada, K. Tsukakoshi, Consideration for Input Current-Ripple Reduction on a Novel Pulse-link DC-AC Converter for Fuel Cells, PESC 2008, pp. 1284-1289, 2008.06.
199. S. Abe, M. Hirokawa, M. Shoyama, T. Ninomiya, Optimal Intermediate Bus Capacitance for System Stability on Distributed Power, PESC 2008, pp. 611-616, 2008.06.
200. K. Fukushima, I. Norigoe, T. Ninomiya, M. Shoyama, Y. Harada, K. Tsukakoshi, Input Current-Ripple Reduction Method on a Novel Pulse-link DC-AC Converter for Fuel Cells Applications, SPEEDAM 2008, pp. 821-825, 2008.06.
201. S. Abe, M. Shoyama, T. Ninomiya, First-Order Transient Response of DC-DC Converter with Peak Current Mode Control for Low-Voltage Application, SPEEDAM 2008, pp. 32-36, 2008.06.
202. K. Fukushima, T. Ninomiya, M. Shoyama, I. Norigoe, Y. Harada, K. Tsukakoshi, Z. Dai, Consideration for the Pulse-link DC-AC Converter for Fuel Cells, IEEE APEC 2008, pp. 298-303, 2008.02.
203. M. Shoyama, and T. Ninomiya, Common-mode Noise Reduction in the Watkins-Johnson Converter, 7th International Conference on Power Electronics (ICPE’07), pp.1,083-1,086, 2007.10.
204. M. Shoyama, Y. Kurokawa, and T. Ninomiya, Common-mode Noise Reduction in the Watkins-Johnson Converter, IEEE 29th INTELEC’07, pp.577-580, 2007.09.
205. M. Shoyama, and T. Ninomiya, Output Voltage Control of Resonant Boost Switched Capacitor Converter, The Fourth Power Conversion Conference (PCC-NAGOYA 2007), No.LS3-4-4, pp.899-903, 2007.04.
206. M. Shoyama, and T. Ninomiya, Common-Mode Noise Reduction Techniques Using Current Cancellation in Switching Power Supplies, 2006 Korea-Japan Joint Conference on AP/EMCJ/EMT (KJCC 2006), pp.197-200, 2006.09.
207. M. Shoyama, F. Deriha, and T. Ninomiya, Evaluation of Conducted Noise of Resonant Switched Capacitor Converter, IEEE International Telecommunications Energy Conference, No.14-3, pp.205-209, 2006.09.
208. M. Shoyama, and T. Ninomiya, Common-Mode Noise Reduction by Current Cancellation in Switching Power Supplies, The 7th International Joint Symposium between Chungnam National University and Kyushu University(第7回忠南大学・九州大学間国際合同シンポジウム), pp.67-70, 2005.09.
209. M. Shoyama, F. Deriha, and T. Ninomiya, Steady-State Characteristics of Resonant Switched Capacitor Converter, Journal of Power Electronics (JPE), Vol.5, No.3, pp.206-211, 2005.07.
210. M. Shoyama, F. Deriha, and T. Ninomiya, Operation Analysis and Control of Resonant Boost Switched Capacitor Converter with High Efficiency, IEEE 36th Power Electronics Specialists Conference (PESC '05) Record, 10.1109/PESC.2005.1581901, 1966-1971, pp.1966-1971, 2005.06.
211. M. Shoyama, T. Tsumura, and T. Ninomiya, Optimum Design Considerations of Balanced Boost Switching Converter to Reduce Common-Mode Conducted Noise, 2005 International Power Electronics Conference (IPEC '05), pp.1150-1154, 2005.04.
212. M. Shoyama, F. Deriha, and T. Ninomiya, Operation Analysis of Resonant Switched Capacitor Converter, 2005 International Power Electronics Conference (IPEC '05), pp.508-512, 2005.04.
213. M. Shoyama, F. Deriha, and T. Ninomiya, Resonant Boost Switched Capacitor Converter with High Efficiency, IEEE International Conf. on Industrial Electronics, Control and Instrumentation (IECON '04), 222-226, No.WC7-2, 2004.11.
214. M. Shoyama, F. Deriha, and T. Ninomiya, Steady-State Characteristics of Resonant Switched Capacitor Converter, 6th International Conference on Power Electronics (ICPE '04), pp.II-137-141, 2004.10.
215. M. Shoyama, M. Ohba, and T. Ninomiya, Common-Mode Noise Reduction by Current Cancellation in Balanced Buck-Boost Switching Converter, 4th International Power Electronics and Motion Control Conference (IPEMC '04), 1505-1510, pp.1505-1510, 2004.08.
216. M. Shoyama, T. Naka, and T. Ninomiya, Resonant Switched Capacitor Converter with High Efficiency, IEEE 35th Power Electronics Specialists Conference (PESC '04) Record, 3780-3786, pp.3780-3786, 2004.06.
217. M. Shoyama, T. Tsumura, and T. Ninomiya, Mechanism of Common-Mode Noise Reduction in Balanced Boost Switching Converter, IEEE 35th Power Electronics Specialists Conference (PESC '04) Record, 1115-1120, pp.1115-1120, 2004.06.
218. T. Ninomiya, M. Shoyama, N. Mutoh, and H. Hayakawa, Common-Mode Noise Reduction Techniques for Switched-Mode Power Converters, 2004 International Symposium on Electromagnetic Compatibility, pp.193-196, 2004.06.
219. M. Shoyama, T. Tsumura, G. Li, and T. Ninomiya, Analysis of Noise Current Cancellation Mechanism in Balanced Boost Switching Converter, 2004 International Symposium on Electromagnetic Compatibility, pp.725-728, 2004.06.
220. M. Shoyama, G. Li, and T. Ninomiya, Balanced Switching Converter to Reduce Common-Mode Conducted Noise, IEEE Transactions on Industrial Electronics, 10.1109/TIE.2003.819677, 50, 6, 1095-1099, Vol.50, No.6, pp.1095-1099, 2003.12.
221. M Shoyama, G Li, T Ninomiya, Balanced switching converter to reduce common-mode conducted noise, IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, 10.1109/TIE.2003.819677, 50, 6, 1095-1099, 2003.12, Because conventional switching converters have usually used unbalanced circuit topologies, parasitic capacitance between the drain/collector of an active switch and the frame ground through its heat sink may generate the common-mode conducted noise. This paper proposes a balanced switching converter circuit, which is an effective way to reduce the common-mode conducted noise. As an example, a boost converter version of the balanced switching converter is presented, and the mechanism of the common-mode noise reduction is explained using an equivalent circuit. This good feature is confirmed by experimental results. The concept of the balanced switching converter is applied to some other types of switching converters..
222. G. Li, M. Shoyama, and T. Ninomiya, Noise Reduction Mechanism in Common-Source Type Active-Clamped DC-DC Converters, IEEE International Telecommunications Energy Conference, 03CH37481, 505-509, pp.505-509, 2003.10.
223. M. Shoyama, M. Ohba, and T. Ninomiya, Common-Mode Noise Reduction by Current Cancellation in Balanced Buck-Boost Switching Converter, IEEE International Telecommunications Energy Conference, 03CH37481, 499-504, pp.499-504, 2003.10.
224. M. Shoyama, T. Tsumura, and T. Ninomiya, Common-Mode Noise Reduction by Current Cancellation in Balanced Boost Switching Converter, 2003 Korea-Japan Joint Symposium on Advanced Industry Applications, pp.18-22, 2003.10.
225. M. Shoyama, G. Li, and T. Ninomiya, Application of Common-Source Active-Clamp Circuit to Various DC-DC Converter Topologies, IEEE Power Electronics Specialists Conference Record, 03CH37427, 1321-1326, pp.1321-1326, 2003.06.
226. M. Shoyama, M. Ohba, and T. Ninomiya, Balanced Buck-Boost Switching Converter to Reduce Common-Mode Conducted Noise, IEEE Power Electronics Specialists Conference Record, 02CH37289, 2056-2061, pp.2056-2061, 2002.06.
227. M. Shoyama, M. Ohba, and T. Ninomiya, Balanced Buck-Boost Switching Converter to Reduce Common-Mode Conducted Noise, Journal of Power Electronics (JPE), Vol.2, No.2, pp.139-145, 2002.04.
228. M. Shoyama, M. Ohba, and T. Ninomiya, Balanced Buck-Boost Switching Converter to Reduce Common-Mode Conducted Noise, 2001 International Conf. on Power Electronics (ICPE), pp.212-216, 2001.10.
229. T. Ninomiya, M. Shoyama, C.F. Jin, and G. Li, EMI Issues in Switching Power Converters, 13th International Symposium on Power Semiconductor Devices & ICs (ISPSD), 81-85, pp.81-85, 2001.06.
230. G. Li, M. Shoyama, T. Ninomiya, and T. Inoue, Common-Mode Noise Reduction in DC-DC Converters by Common-Source Type Active-Clamp Technique, IEEE Power Electronics Specialists Conference Record, 01CH37230, 1773-1778, pp.1773-1778, 2001.06.
231. M. Shoyama, T. Okunaga, G. Li, and T. Ninomiya, Balanced Switching Converter to Reduce Common-Mode Conducted Noise, IEEE Power Electronics Specialists Conference Record, 01CH37230, 451-456, pp.451-456, 2001.06.
232. T Kohama, T Ninomiya, M Shoyama, F Ihara, Static and dynamic analysis of paralleled dc-to-dc converter system with averaged current-balancing controllers, ELECTRONICS AND COMMUNICATIONS IN JAPAN PART I-COMMUNICATIONS, 84, 5, 67-75, 2001.05, Analysis and experiment are carried out for the current balancing characteristics of the parallel dc-dc converter system with averaged current-balancing controllers. The suppression effect of the current unbalance caused by the difference in the module parameters in the static and dynamic characteristics is quantitatively determined. With regard to the instability inside the parallel system caused by the current-balancing control with a phase delay, the phenomena are presented and the stable operating region is derived. (C) 2001 Scripta Technica..
233. T Mizoguchi, T Ninomiya, T Ohgai, M Shoyama, A family of single-switch ZVS-CV dc-to-dc converters, IEICE TRANSACTIONS ON COMMUNICATIONS, E79B, 6, 849-856, 1996.06, A family of single-switch ZVS-CV (Zero-voltage switching - clamped voltage) dc-to-dc converters is presented. This class of converter is realized by employing a commutation inductor circuit which is connected in parallel with either the transistor or the freewheeling diode in a conventional PWM converter. The technique described here is simple and output-voltage control is easy. The converters that comprise this family are derived from Buck, Boost, Buck/Boost, Cuk, Sepic and Zeta PWM converters. The steady-state characteristics of these converters such as the voltage conversion ratio, the ZVS conditions, and the input and output current ripples are analyzed. The analysis is confirmed by experiment..
234. M Shoyama, T Kurachi, T Ninomiya, Ripple current analysis of an electrolytic capacitor in power factor correctors, ELECTRONICS AND COMMUNICATIONS IN JAPAN PART II-ELECTRONICS, 79, 4, 93-101, 1996.04, A large electrolytic capacitor usually is employed at the output terminal of power factor correction circuits to suppress the high-frequency switching ripple voltage as well as the low-frequency ripple voltage. Due to the equivalent series resistance of the electrolytic capacitor, the capacitor current causes power loss which increases its temperature and may shorten its life. Thus, it is important to estimate accurately the effective value of the capacitor current for a proper choice of the capacitor and to maintain the expected life of the capacitor.
This paper presents a detailed analysis of the ripple current of an electrolytic capacitor in the boost-type power factor correction circuit. The ripple current is divided into two components, namely, the low-frequency and the high-frequency components. The root-mean-square value of the capacitor current is divided for both frequency components. The analytical results are confirmed by experiments..
Membership in Academic Society
  • The Institute of Electrical and Electronics Engineers, Inc.
  • The Institute of Electronics, Information and Communication Engineers
  • The Institute of Electrical Engineers of Japan
  • The Society of Instrument and Control Engineers
Awards
  • He has made outstanding achievements in research and education on switching power supply technology for electronic information communication.
  • In gratitude and appreciation for your efforts to the success of the 37th International Telecommunications Energy Conference
  • Contribution to the progress of Electronics, Information and Communications Engineering, and Related science and technology as an IEICE Member
  • In gratitude and appreciation of your hard work, effort and enthusiasm given so generously to help make the IPEC-Hiroshima 2014 which was held during May 18-21, an outstanding success
  • "Variable Step Size Maximum Power Point Tracker Using Single Variable for Stand-alone Battery Storage PV Systems", published in Journal of Power Electronics (JPE), Vol.11, No.2, pp.218-227, March, 2011.
  • Noise Current Characteristics of Semiconductor Circuit Breaker during Break-Off Condition in DC Power Supply System
  • In recognition of professional standing the Officers and Board of Directors of the IEEE certify that Masahito Shoyama has been elected to the grade of Senior Member.
Social
Professional and Outreach Activities
-------------------------------------------------- ---------------------------------
At Fukuoka System LSI College, Fukuoka Industry and Science Promotion Foundation
Textbooks used in the "Power Electronics Course":
Supervised "Basics of Power Electronics" (published on June 18, 2012, 1st edition, 1st edition)
Contribution to "Power Electronics Electric Circuit Basics" (Issue 1st edition, September 11, 2012)
-------------------------------------------------- ---------------------------------
Sponsored by Kitakyushu International Technical Cooperation Association (KITA)
Japan International Cooperation Agency (JICA) training: In cooperation with the "Solar energy generation technology course",
On Tuesday, March 13, 2012, he gave the following lecture and gave experimental guidance.
"Maximum Power Point Tracking (MPPT) in photovoltaic (PV) Systems:
Converter Topology, Tracking algorithms, Simulation and Experimental Results",
Emad M. Ahmed & Masahito Shoyama
-------------------------------------------------- ---------------------------------
Dispatched from Fukuoka System LSI College, Fukuoka Prefecture Industry and Science Promotion Foundation,
I gave a lecture on "Power Electronics Course" at the following two places.
Power Electronics Beginner (September 6, 2011, Yokohama City)
Power Electronics Intermediate (September 20-21, 2011, Hirakata City)
-------------------------------------------------- ---------------------------------.