The Experts below are selected from a list of 1197 Experts worldwide ranked by ideXlab platform
Mutsuo Nakaoka - One of the best experts on this subject based on the ideXlab platform.
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analysis design and performance evaluations of an edge resonant switched capacitor cell assisted soft switching pwm boost dc dc converter and its interleaved topology
IEEE Transactions on Power Electronics, 2013Co-Authors: Tomokazu Mishima, Yujiro Takeuchi, Mutsuo NakaokaAbstract:This paper presents a soft-switching pulsewidth modulation (PWM) nonisolated boost dc-dc converter embedding an edge-resonant switched capacitor (ER-SWC) cell and its interleaved circuit topology. The conceptual boost dc-dc converter treated herein can achieve high-frequency zero-current soft-switching turn-on and zero-voltage soft-switching turn-off operations in the active switches and minimization of a reverse recovering current in the Freewheeling Diode under discontinuous conduction mode partially including critical conduction mode in the input current. Those advantageous properties enable a wide range of soft-switching operations together with a high-voltage step-up conversion ratio with a reduced current stress. Circuit design guideline based on the soft-switching range is introduced; then, a theoretical analysis is carried out for investigating the step-up voltage conversion ratio. For demonstrating the effectiveness of the ER-SWC soft-switching PWM boost dc-dc converter and its newly developed interleaved topology, laboratory prototypes are evaluated in experiments; then, their performances are discussed from a practical point of view.
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a new high step up voltage ratio soft switching pwm boost dc dc power converter with edge resonant switched capacitor modular
European Conference on Power Electronics and Applications, 2011Co-Authors: Tomoakzu Mishima, Yujiro Takeuchi, Mutsuo NakaokaAbstract:This paper presents a new soft switching PWM non-isolated boost DC-DC converter embedding an edge resonant switched capacitor (ER-SWC) modular. The soft switching PWM boost DC-DC converter treated here can achieve a high frequency zero current switching (ZCS) turn-on and zero voltage switching (ZVS) turn-off operations in active switches and minimize a reverse recovering current in the Freewheeling Diode under DCM including CRM conditions in the input inductor current. Those advantageous properties enable a wide range of soft switching operations together with a high step-up voltage conversion ratio due to the edge resonance in the ER-SWC modular, which results in the high efficiency power conversion. For demonstrating the effectiveness of the new soft switching PWM boost DC-DC converter, a 1kW–40kHz laboratory prototype is evaluated in experiments, followed by the design guideline of the DC-DC converter and a theoretical analysis. Then, the performances of the proposed soft switching PWM boost DC-DC converter are discussed from a practical point of view.
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High-frequency isolated soft-switching phase-shift PWM DC-DC power converter using tapped inductor filter : Powering the broadband network
2004Co-Authors: Sergey Moiseev, Koji Soshin, Mutsuo NakaokaAbstract:In this paper, a novel type of the step-up high frequency transformer linked full-bridge soft-switching phase-shift PWM DC-DC power converter with ZVS and ZCS bridge legs is proposed for small scale fuel cell power generation systems, automotive AC power supplies. A tapped inductor filter with a Freewheeling Diode is implemented in the proposed soft-switching DC-DC power converter to minimize the circulating current in the high-frequency step-up transformer primary side and high-frequency inverter stage. Using a tapped inductor filter with a Freewheeling Diode makes possible to reduce the circulating current without any active switches and theirs gate-drive circuits. The operating principle of the proposed DC-DC power converter with each operation mode during a half cycle of the steady state operation is explained. The optimum design of the tapped inductor turns ratio is described on the basis of the circuit simulation results. Developing 1 kW 100kHz prototype with power MOSFETs and 36 V DC source verifies the practical effectiveness of the proposed soft-switching DC-DC power converter. The actual efficiency of the proposed DC-DC power converter is obtained 94% for the wide load and output voltage variation ranges.
Masahiro Takasaki - One of the best experts on this subject based on the ideXlab platform.
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A Surgeless Solid-State DC Circuit Breaker for Voltage-Source-Converter-Based HVDC Systems
IEEE Transactions on Industry Applications, 2014Co-Authors: Kenichiro Sano, Masahiro TakasakiAbstract:This paper proposes a dc circuit breaker for voltage source converter (VSC) based high-voltage dc transmission (HVDC) systems. Technical challenges for applying dc circuit breakers are to increase blocking voltage and to suppress surge voltage at the current clearing. The proposed dc circuit breaker is a solid-state breaker which consists of a number of semiconductor devices in series. It maintains equal voltage balancing among the devices to apply it to high-voltage applications. Moreover, the surge voltage across the circuit breaker is reduced by employing a Freewheeling Diode. Considering a system rated at 300 MW in power and 250 kV in dc voltage, the conduction loss of the proposed circuit breaker is estimated to be 0.045% of the rated power. The value is smaller than the power loss of the VSCs. A downscaled HVDC system rated at 10 kW in power and 360 V in dc voltage was built and tested. A series of experimental results demonstrates the dc fault clearing and rapid restoration of power transmission.
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A surge-less solid-state dc circuit breaker for voltage source converter based HVDC transmission systems
2012 IEEE Energy Conversion Congress and Exposition (ECCE), 2012Co-Authors: Kenichiro Sano, Masahiro TakasakiAbstract:This paper proposes a dc circuit breaker for voltage source converter (VSC) based high voltage dc (HVDC) transmission systems. The dc circuit breaker is a solid-state breaker which consists of many semiconductor devices in series with maintaining equal voltage balancing, making it possible to apply to high voltage applications. Moreover, the surge voltage across the circuit breaker is reduced by employing a Freewheeling Diode. In a system rated at 300 MW in power and 250 kV in dc voltage, conduction loss of the proposed circuit breaker consisting of 4.5 kV devices is estimated at 0.045% of the rated power, which is enough small comparing to the VSCs' power loss. A downscaled HVDC transmission system model rated at 10 kW in power and 360 V in dc voltage was built and a series of experimental results demonstrate the dc fault clearing and rapid restoration of power transmission.
Ahmad J. Sebzali - One of the best experts on this subject based on the ideXlab platform.
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A new class of quasi-square-wave resonant converters with ZCS
Energy Conversion and Management, 1998Co-Authors: Esam H. Ismail, Ahmad J. SebzaliAbstract:Abstract A new class of single-switch zero-current switching and clamped current (ZCS-CC) d.c.–d.c. converters is proposed. These converters can be realized by connecting a resonant tank inductor and a Diode in series with the active switch in a conventional PWM converter, while a parallel combination of a filter inductor and a tank capacitor is connected in series with the Freewheeling Diode. All the semiconductors in these converters switch at ZCS-CC with minimum current stress, while the Freewheeling Diode turns on at ZVS. Moreover, the variation in the semiconductors voltage stress is relatively low at full and minimum load. The steady state characteristics for the complete class are analysed and verified.
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A new class of quasi-square wave resonant converters with ZCS
PESC97. Record 28th Annual IEEE Power Electronics Specialists Conference. Formerly Power Conditioning Specialists Conference 1970-71. Power Processing, 1Co-Authors: Esam H. Ismail, Ahmad J. SebzaliAbstract:A new class of a single-switch zero-current switching and clamped current (ZCS-CC) DC-DC power converters are proposed. These power converters can be realized by connecting a resonant tank inductor and a Diode in series with the active switch in a conventional PWM power converter, while a parallel combination of a filter inductor and a tank capacitor is connected in series with the Freewheeling Diode. All the semiconductors in these power converters switch at ZCS with minimum current stress, while the Freewheeling Diode turns-on at ZVS. Moreover, the variation in the semiconductor voltage stresses are relatively low at either full and minimum load. The steady-state characteristics for the complete power converter class are analyzed and verified.
Kenichiro Sano - One of the best experts on this subject based on the ideXlab platform.
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A Surgeless Solid-State DC Circuit Breaker for Voltage-Source-Converter-Based HVDC Systems
IEEE Transactions on Industry Applications, 2014Co-Authors: Kenichiro Sano, Masahiro TakasakiAbstract:This paper proposes a dc circuit breaker for voltage source converter (VSC) based high-voltage dc transmission (HVDC) systems. Technical challenges for applying dc circuit breakers are to increase blocking voltage and to suppress surge voltage at the current clearing. The proposed dc circuit breaker is a solid-state breaker which consists of a number of semiconductor devices in series. It maintains equal voltage balancing among the devices to apply it to high-voltage applications. Moreover, the surge voltage across the circuit breaker is reduced by employing a Freewheeling Diode. Considering a system rated at 300 MW in power and 250 kV in dc voltage, the conduction loss of the proposed circuit breaker is estimated to be 0.045% of the rated power. The value is smaller than the power loss of the VSCs. A downscaled HVDC system rated at 10 kW in power and 360 V in dc voltage was built and tested. A series of experimental results demonstrates the dc fault clearing and rapid restoration of power transmission.
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A surge-less solid-state dc circuit breaker for voltage source converter based HVDC transmission systems
2012 IEEE Energy Conversion Congress and Exposition (ECCE), 2012Co-Authors: Kenichiro Sano, Masahiro TakasakiAbstract:This paper proposes a dc circuit breaker for voltage source converter (VSC) based high voltage dc (HVDC) transmission systems. The dc circuit breaker is a solid-state breaker which consists of many semiconductor devices in series with maintaining equal voltage balancing, making it possible to apply to high voltage applications. Moreover, the surge voltage across the circuit breaker is reduced by employing a Freewheeling Diode. In a system rated at 300 MW in power and 250 kV in dc voltage, conduction loss of the proposed circuit breaker consisting of 4.5 kV devices is estimated at 0.045% of the rated power, which is enough small comparing to the VSCs' power loss. A downscaled HVDC transmission system model rated at 10 kW in power and 360 V in dc voltage was built and a series of experimental results demonstrate the dc fault clearing and rapid restoration of power transmission.
Esam H. Ismail - One of the best experts on this subject based on the ideXlab platform.
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A new class of quasi-square-wave resonant converters with ZCS
Energy Conversion and Management, 1998Co-Authors: Esam H. Ismail, Ahmad J. SebzaliAbstract:Abstract A new class of single-switch zero-current switching and clamped current (ZCS-CC) d.c.–d.c. converters is proposed. These converters can be realized by connecting a resonant tank inductor and a Diode in series with the active switch in a conventional PWM converter, while a parallel combination of a filter inductor and a tank capacitor is connected in series with the Freewheeling Diode. All the semiconductors in these converters switch at ZCS-CC with minimum current stress, while the Freewheeling Diode turns on at ZVS. Moreover, the variation in the semiconductors voltage stress is relatively low at full and minimum load. The steady state characteristics for the complete class are analysed and verified.
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A new class of quasi-square wave resonant converters with ZCS
PESC97. Record 28th Annual IEEE Power Electronics Specialists Conference. Formerly Power Conditioning Specialists Conference 1970-71. Power Processing, 1Co-Authors: Esam H. Ismail, Ahmad J. SebzaliAbstract:A new class of a single-switch zero-current switching and clamped current (ZCS-CC) DC-DC power converters are proposed. These power converters can be realized by connecting a resonant tank inductor and a Diode in series with the active switch in a conventional PWM power converter, while a parallel combination of a filter inductor and a tank capacitor is connected in series with the Freewheeling Diode. All the semiconductors in these power converters switch at ZCS with minimum current stress, while the Freewheeling Diode turns-on at ZVS. Moreover, the variation in the semiconductor voltage stresses are relatively low at either full and minimum load. The steady-state characteristics for the complete power converter class are analyzed and verified.
