Hyoung-Sup Cho

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This paper proposes a high-efficiency soft-switching pulse-width modulated (PWM) full-bridge (FB) dc-dc converter for the on-board battery charger of electric vehicles (EVs). Asymmetrical PWM (APWM) FB converter is proposed with zero-voltage switching (ZVS) of the power switches and zero-current switching (ZCS) of an output diode. Switching losses can be(More)
This paper proposes a high-frequency-link soft-switching pulse-width modulated dc-dc converter for electric vehicle (EV) on-board battery chargers. Zero-voltage switching of power switches is achieved from light load to full load. Reverse-recovery losses can be reduced in the secondary side output diodes without using any additional circuit components.(More)
This paper proposes a high-efficiency pulse-width modulated (PWM) full-bridge (FB) dc-dc converter for automotive battery charging applications. The proposed PWM FB converter has a wide zero-voltage switching (ZVS) range with a current doubler rectifier (CDR) for low-voltage battery chargers. Compared to the conventional phase-shift modulated (PSM) FB(More)
This paper presents a high efficiency step-up DC-DC converter for low-DC renewable energy sources. The proposed DC-DC converter is controlled by asymmetrical pulse width modulation(APWM) technique and achieves Zero-current switching(ZCS) of all output diodes. Compared to the previous DC-DC converters, the voltage stresses of the semiconductor devices can be(More)
This paper proposes a high efficiency power conversion system (PCS) for battery-ultracapacitor hybrid energy storages. The proposed system has only one bidirectional dc-dc converter for hybrid power source with batteries and ultracapacitors. The hybrid power source has bidirectional switching circuits for selecting one energy storage device. Bidirectional(More)
This paper proposes a high-efficiency ultracapacitor charger using a soft-switching full-bridge pulse-width modulated (PWM) converter. Conventional full-bridge phase-shift modulated (PSM) converter is used for charging ultracapacitors. However, the power efficiency of conventional converters is low because of its circulating current and high output diode(More)
This paper proposes a high-efficiency softswitching dc-dc converter for electric vehicle battery chargers. All power switches achieve zero-voltage switching with the complementary pulsewidth modulation. Power switches can be actively-clamped with no increase in conduction losses. All output diodes achieve zero-current switching without any voltage(More)
This paper proposes a bridgeless half-bridge ac-dc converter with series-connected two transformers. The proposed converter integrates the operation of the bridgeless power factor correction (PFC) boost rectifier and the asymmetrical pulse-width modulation half-bridge dc-dc converter. The proposed converter provides an isolated dc output voltage without any(More)
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