EPE Association: EPE 2013 - LS9d: Soft Switching Converters

EPE 2013 - LS9d: Soft Switching Converters
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2013 ECCE Europe - Conference > EPE 2013 - Topic 04: Soft switching converters and control > EPE 2013 - LS9d: Soft Switching Converters

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   Elimination of switching losses in the single active bridge over a wide voltage and load range at constant frequency
By Yeh TING, Sjoerd DE HAAN, J.A. FERREIRA [View]
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Abstract: Switching losses occur in the single active bridge (SAB) with phase-shift control when it operates over a large voltage and load range at constant frequency. At high output current, the SAB operates in continuous conduction mode (CCM) where the anti-parallel diode of the switch conducts prior to the switch turning on, thus enabling ZVS. However at low output current, zero current switching (ZCS) turn-off occurs in discontinuous conduction mode (DCM) and ZVS turn-on is lost. With the dual current pulse control proposed in this paper where a non-zero turn-off current is maintained during DCM, switching losses can be mostly eliminated across large output current range with a simple auxiliary circuit, hence enabling large voltage and load variations at higher efficiency. Efficiency increase of up to 12 \% at light-load can be achieved without sacrificing its full-load efficiency. The predicted results are validated with a 3 kW SAB hardware prototype.

   High Frequency PWM-Controlled Current-Mode Resonant DC-DC Converter with Boost Conversion
By Akinori HARIYA, Ken MATSUURA, Hiroshige YANAGI, Satoshi TOMIOKA, Yoichi ISHIZUKA, Tamotsu NINOMIYA [View]
[Download]

Abstract: In this paper, a new pulse width modulation (PWM) control method for the isolated current-mode resonant converter with a fixed switching frequency is presented. The circuit topology is the same as a conventional resonant converter with synchronous rectification and without any additional components. The control technique for the output voltage regulation is proposed with the unique PWM control for synchronously-rectifying switches. By using the transformer’s leakage inductance and the PWM control, the boost conversion can be realized. Also, the zero-voltage switching (ZVS) operation can be done for primary switches, simultaneously. Some experiments have been done with 5MHz isolated DC-DC converter which has Gallium Nitride field effect transistor (GaN-FET).

   Very High Frequency Interleaved Self-Oscillating Resonant SEPIC Converter
By Milovan KOVACEVIC, Arnold KNOTT, Michael ANDERSEN [View]
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Abstract: This paper describes analysis and design procedure of an interleaved, self-oscillating resonant SEPICconverter, suitable for operation at very high frequencies (VHF) ranging from 30 MHz to 300 MHz.The presented circuit consists of two resonant SEPIC DC-DC converters, and a capacitive interconnection network between the switches which provides self-oscillating and interleaved operation. A designapproach to ensure zero voltage switching (ZVS) condition of the MOSFET devices is provided.To verify the proposed method, a 11 W, 50 MHz prototype was built using low-cost VDMOS devicesand experimental results are presented. Peak achieved efficiency was 87\%.

EPE 2013 - LS9d: Soft Switching Converters
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2013 ECCE Europe - Conference > EPE 2013 - Topic 04: Soft switching converters and control > EPE 2013 - LS9d: Soft Switching Converters
	[return to parent folder]

	Elimination of switching losses in the single active bridge over a wide voltage and load range at constant frequency By Yeh TING, Sjoerd DE HAAN, J.A. FERREIRA	[View] [Download]
Abstract: Switching losses occur in the single active bridge (SAB) with phase-shift control when it operates over a large voltage and load range at constant frequency. At high output current, the SAB operates in continuous conduction mode (CCM) where the anti-parallel diode of the switch conducts prior to the switch turning on, thus enabling ZVS. However at low output current, zero current switching (ZCS) turn-off occurs in discontinuous conduction mode (DCM) and ZVS turn-on is lost. With the dual current pulse control proposed in this paper where a non-zero turn-off current is maintained during DCM, switching losses can be mostly eliminated across large output current range with a simple auxiliary circuit, hence enabling large voltage and load variations at higher efficiency. Efficiency increase of up to 12 \% at light-load can be achieved without sacrificing its full-load efficiency. The predicted results are validated with a 3 kW SAB hardware prototype.

	High Frequency PWM-Controlled Current-Mode Resonant DC-DC Converter with Boost Conversion By Akinori HARIYA, Ken MATSUURA, Hiroshige YANAGI, Satoshi TOMIOKA, Yoichi ISHIZUKA, Tamotsu NINOMIYA	[View] [Download]
Abstract: In this paper, a new pulse width modulation (PWM) control method for the isolated current-mode resonant converter with a fixed switching frequency is presented. The circuit topology is the same as a conventional resonant converter with synchronous rectification and without any additional components. The control technique for the output voltage regulation is proposed with the unique PWM control for synchronously-rectifying switches. By using the transformer’s leakage inductance and the PWM control, the boost conversion can be realized. Also, the zero-voltage switching (ZVS) operation can be done for primary switches, simultaneously. Some experiments have been done with 5MHz isolated DC-DC converter which has Gallium Nitride field effect transistor (GaN-FET).

	Very High Frequency Interleaved Self-Oscillating Resonant SEPIC Converter By Milovan KOVACEVIC, Arnold KNOTT, Michael ANDERSEN	[View] [Download]
Abstract: This paper describes analysis and design procedure of an interleaved, self-oscillating resonant SEPICconverter, suitable for operation at very high frequencies (VHF) ranging from 30 MHz to 300 MHz.The presented circuit consists of two resonant SEPIC DC-DC converters, and a capacitive interconnection network between the switches which provides self-oscillating and interleaved operation. A designapproach to ensure zero voltage switching (ZVS) condition of the MOSFET devices is provided.To verify the proposed method, a 11 W, 50 MHz prototype was built using low-cost VDMOS devicesand experimental results are presented. Peak achieved efficiency was 87\%.