EPE Association: EPE 2005 - Topic 03-2 - LS: Soft switching converters (resonant, ZVS, ZCS)

EPE 2005 - Topic 03-2 - LS: Soft switching converters (resonant, ZVS, ZCS)
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2005 - Conference > EPE 2005 - Topic 03: SOFT SWITCHING CONVERTERS AND CONTROL > EPE 2005 - Topic 03-2 - LS: Soft switching converters (resonant, ZVS, ZCS)

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   A NEW IMPLEMENTATION of HIGH VOLTAGE, HIGH FREQUENCY DIRECT POWER CONVERTER
By CLARE Jon; WHEELER Patrick; DANG Huy Quoc Si [View]
[Download]

Abstract: This paper presents an analysis of a predictive control and its digital implementation on a high voltage, ultrasonic resonant frequency (20 kHz) direct power converter (DPC). An extension of the input current prediction is proposed to enable the practical implementation of the control technique. Results from a simulation study and from a prototype converter are presented. Good correlation between simulation and experimental results measured on a prototype are shown, confirming the feasibility of the approach.

   A single switch buck-boost converter with a high conversion ratio
By MELKEBEEK Jan; VAN DE SYPE David; VAN DEN BOSSCHE Alex; RYCKAERT Wouter; DE GUSSEME Koen [View]
[Download]

Abstract: To supply a high voltage load from a low voltage source (e.g. battery pack) often a converter is required with a high conversion ratio. Boost converter topologies with coupled inductors have emerged displaying a high efficiency, a low overall component count, a simple topology, and the need for only a single low-voltage active switch. However, in some applications the output of the converter must be capable of reaching voltages below the input voltage. To solve this problem, a buck-boost-converter topology can be derived from the boost converter with coupled inductors. However, if the different positions for the capacitors in the buck-boost topology are considered, several variants can be distinguished. The properties of the different topological variations are studied. Eventually, a topological choice is made based on the proposed criteria for a 175-V supply, converting 175 W from a 24-V battery. The theoretical results are compared to the results retrieved from a prototype converter.

   Polyphase Boost Converter for Automotive and UPF Applications
By RAMANARAYANAN Venkataraman; MIRZAEI Rahmatollah [View]
[Download]

Abstract: Boost dc-to-dc converters have very good source interface properties. The input inductor makes the source current smooth and hence these converters provide very good EMI performance. On account of this good property, the boost converter is also the preferred converter for off-line UPF rectifiers. One of the issues of concern in these converters is the large size of the storage capacitor on the dc link. The boost converter suffers from the disadvantage of discontinuous current injected to the load. The size of the capacitor is therefore large. Further, the ripple current in the capacitor is as much as the load current; hence the ESR specification of the tank capacitor is quite demanding. This is specially so in the emerging application areas of automotive power conversion, where the input voltage is low (typically 12V) and large voltage boost (4 to 5) are desired. In the UPF rectifier applications, the input voltage varies from zero to maximum value twice in every cycle of the ac input voltage. The duty cycle therefore varies in the full range of zero to one. The inductor current varies from zero to rated current twice in every ac cycle of the input current. On account of these wide operating point variations, the design of the power circuit as well as the closed loop controller is a demanding task. This paper suggests polyphase operation of boost converter to overcome the disadvantages of large size storage capacitor in boost converter and off-line UPF rectifiers and a small signal analysis of N converters in parallel to an equivalent second order system in such converters, which have not been considered in previous works.

   Self-oscillating sine wave oscillator for ferrite loss measurements
By NIKOLOV Georgi; VAN DEN BOSSCHE Alex; VALCHEV Vencislav; MELKEBEEK Jan [View]
[Download]

Abstract: A self-oscillating sine-wave oscillator is proposed with a frequency range from 20kHz up to 2MHz. The voltage amplitude ranges from 10V, up to 350V peak. A stepwise selectable capacitor and a variable inductor are used to adapt the frequency. Also DC injection in the test object is possible. It is mainly intended for measurement of losses in ferrite cores.

EPE 2005 - Topic 03-2 - LS: Soft switching converters (resonant, ZVS, ZCS)
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2005 - Conference > EPE 2005 - Topic 03: SOFT SWITCHING CONVERTERS AND CONTROL > EPE 2005 - Topic 03-2 - LS: Soft switching converters (resonant, ZVS, ZCS)
	[return to parent folder]

	A NEW IMPLEMENTATION of HIGH VOLTAGE, HIGH FREQUENCY DIRECT POWER CONVERTER By CLARE Jon; WHEELER Patrick; DANG Huy Quoc Si	[View] [Download]
Abstract: This paper presents an analysis of a predictive control and its digital implementation on a high voltage, ultrasonic resonant frequency (20 kHz) direct power converter (DPC). An extension of the input current prediction is proposed to enable the practical implementation of the control technique. Results from a simulation study and from a prototype converter are presented. Good correlation between simulation and experimental results measured on a prototype are shown, confirming the feasibility of the approach.

	A single switch buck-boost converter with a high conversion ratio By MELKEBEEK Jan; VAN DE SYPE David; VAN DEN BOSSCHE Alex; RYCKAERT Wouter; DE GUSSEME Koen	[View] [Download]
Abstract: To supply a high voltage load from a low voltage source (e.g. battery pack) often a converter is required with a high conversion ratio. Boost converter topologies with coupled inductors have emerged displaying a high efficiency, a low overall component count, a simple topology, and the need for only a single low-voltage active switch. However, in some applications the output of the converter must be capable of reaching voltages below the input voltage. To solve this problem, a buck-boost-converter topology can be derived from the boost converter with coupled inductors. However, if the different positions for the capacitors in the buck-boost topology are considered, several variants can be distinguished. The properties of the different topological variations are studied. Eventually, a topological choice is made based on the proposed criteria for a 175-V supply, converting 175 W from a 24-V battery. The theoretical results are compared to the results retrieved from a prototype converter.

	Polyphase Boost Converter for Automotive and UPF Applications By RAMANARAYANAN Venkataraman; MIRZAEI Rahmatollah	[View] [Download]
Abstract: Boost dc-to-dc converters have very good source interface properties. The input inductor makes the source current smooth and hence these converters provide very good EMI performance. On account of this good property, the boost converter is also the preferred converter for off-line UPF rectifiers. One of the issues of concern in these converters is the large size of the storage capacitor on the dc link. The boost converter suffers from the disadvantage of discontinuous current injected to the load. The size of the capacitor is therefore large. Further, the ripple current in the capacitor is as much as the load current; hence the ESR specification of the tank capacitor is quite demanding. This is specially so in the emerging application areas of automotive power conversion, where the input voltage is low (typically 12V) and large voltage boost (4 to 5) are desired. In the UPF rectifier applications, the input voltage varies from zero to maximum value twice in every cycle of the ac input voltage. The duty cycle therefore varies in the full range of zero to one. The inductor current varies from zero to rated current twice in every ac cycle of the input current. On account of these wide operating point variations, the design of the power circuit as well as the closed loop controller is a demanding task. This paper suggests polyphase operation of boost converter to overcome the disadvantages of large size storage capacitor in boost converter and off-line UPF rectifiers and a small signal analysis of N converters in parallel to an equivalent second order system in such converters, which have not been considered in previous works.

	Self-oscillating sine wave oscillator for ferrite loss measurements By NIKOLOV Georgi; VAN DEN BOSSCHE Alex; VALCHEV Vencislav; MELKEBEEK Jan	[View] [Download]
Abstract: A self-oscillating sine-wave oscillator is proposed with a frequency range from 20kHz up to 2MHz. The voltage amplitude ranges from 10V, up to 350V peak. A stepwise selectable capacitor and a variable inductor are used to adapt the frequency. Also DC injection in the test object is possible. It is mainly intended for measurement of losses in ferrite cores.