A Driving Scheme Using a Single Control Signal for a ZVT Voltage Driven Synchronous Buck Converter

Asghari, Amin,Farzanehfard, Hosein The Korean Institute of Power Electronics 2014 JOURNAL OF POWER ELECTRONICS Vol.14 No.2

This paper deals with the optimization of the driving techniques for the ZVT synchronous buck converter proposed in [1]. Two new gate drive circuits are proposed to allow this converter to operate by only one control signal as a 12V voltage regulator module (VRM). Voltage-driven method is applied for the synchronous rectifier. In addition, the control signal drives the main and auxiliary switches by one driving circuit. Both of the circuits are supplied by the input voltage. As a result, no supply voltage is required. This approach decreases both the complexity and cost in converter hardware implementation and is suitable for practical applications. In addition, the proposed SR driving scheme can also be used for many high frequency resonant converters and some high frequency discontinuous current mode PWM circuits. The ZVT synchronous buck converter with new gate drive circuits is analyzed and the presented experimental results confirm the theoretical analysis.

Family of Isolated Zero Current Transition PWM Converters

Adib, Ehsan,Farzanehfard, Hosein The Korean Institute of Power Electronics 2009 JOURNAL OF POWER ELECTRONICS Vol.9 No.2

In this paper a family of zero current transition PWM converters which employs a simple auxiliary circuit is introduced. This soft switched auxiliary circuit is only composed of a switch and a capacitor. The proposed converters are analyzed and various operating modes of the ZCT flyback converter are discussed. Design considerations are presented and the experimental results of the ZCT flyback converter laboratory prototype are illustrated. The experimental results confirm the validity of theoretical analysis.

A New Soft Switching Step-Down/Up Converter with Inherent PFC Performance

Jabbari, Masoud,Farzanehfard, Hosein The Korean Institute of Power Electronics 2009 JOURNAL OF POWER ELECTRONICS Vol.9 No.6

In this paper a new buck-boost type DC-DC converter is presented. Its voltage gain is positive, all active elements operate under soft-switching condition independent of loading, magnetic isolation and self output short-circuit protection exist, and very fast dynamic operation is achievable by a simple bang-bang controller. This converter also exhibits appropriate PFC characteristics since its input current is inherently proportional to the source voltage. When the voltage source is off-line, it is sufficient to add an inductor after the rectifier, then near unity power factor is achievable. All essential guidelines to design the converter as a DC-DC and a PFC regulator are presented. Simulation and experimental results verify the developed theoretical analysis.

A New Zero Voltage Transition Bridgeless PFC with Reduced Conduction Losses

Mahdavi, Mohammad,Farzanehfard, Hosein The Korean Institute of Power Electronics 2009 JOURNAL OF POWER ELECTRONICS Vol.9 No.5

In this paper a new zero voltage transition PWM bridgeless PFC is introduced. The auxiliary circuit provides soft switching condition for all semiconductor devices. Also, in the resonant path of the auxiliary circuit, only two semiconductor devices exist. Therefore the resonant conduction losses are low. Furthermore, the auxiliary circuit semiconductor elements consist of only one diode and one switch. The proposed auxiliary circuit is applied to a bridgeless PFC converter to further reduce conduction and switching losses. In this paper, the operating modes of this converter are explained and the resulting ideal and simulation waveforms are shown. The presented experimental results justify the theoretical analysis.

Isolated Topologies of Switched-Resonator Converters

Jabbari, Masoud,Farzanehfard, Hosein,Shahgholian, Ghazanfar The Korean Institute of Power Electronics 2010 JOURNAL OF POWER ELECTRONICS Vol.10 No.2

Switched-resonator converters are a new family of soft switching DC-DC converters where the energy is transferred via a resonator. This paper introduces some isolated topologies of this family. The achieved advantages include, load independent soft-switching, self short-circuit protection, and optimization capability due to topology variety. Compared to conventional series-resonant converters, outstanding advantages such as a smaller fewer number of switches and diodes, a smaller transformer, and lower current stresses are achieved. A general synthesis scheme, functional topologies, and essential relations are included. Experimental results from a laboratory prototype confirm the presented theoretical analysis.

A Fully Soft Switched Two Quadrant Bidirectional Soft Switching Converter for Ultra Capacitor Interface Circuits

Mirzaei, Amin,Farzanehfard, Hosein,Adib, Ehsan,Jusoh, Awang,Salam, Zainal The Korean Institute of Power Electronics 2011 JOURNAL OF POWER ELECTRONICS Vol.11 No.1

This paper describes a two quadrant bidirectional soft switching converter for ultra capacitor interface circuits. The total efficiency of the energy storage system in terms of size and cost can be increased by a combination of batteries and ultra capacitors. The required system energy is provided by a battery, while an ultra capacitor is used at high load power pulses. The ultra capacitor voltage changes during charge and discharge modes, therefore an interface circuit is required between the ultra capacitor and the battery. This interface circuit must have good efficiency while providing bidirectional power conversion to capture energy from regenerative braking, downhill driving and the protecting ultra capacitor from immediate discharge. In this paper a fully soft switched two quadrant bidirectional soft switching converter for ultra capacitor interface circuits is introduced and the elements of the converter are reduced considerably. In this paper, zero voltage transient (ZVT) and zero current transient (ZCT) techniques are applied to increase efficiency. The proposed converter acts as a ZCT Buck to charge the ultra capacitor. On the other hand, it acts as a ZVT Boost to discharge the ultra capacitor. A laboratory prototype converter is designed and realized for hybrid vehicle applications. The experimental results presented confirm the theoretical and simulation results.

Classification and Comparison of EMI Mitigation Techniques in Switching Power Converters – A Review

Mohammad Rouhollah Yazdani,Hosein Farzanehfard,Jawad Faiz 전력전자학회 2011 JOURNAL OF POWER ELECTRONICS Vol.11 No.5

Power electronic systems such as switching power supplies are accounted as noise sources for other sensitive circuits. EMI caused by power converters can disturb the normal operation of the converter and other adjacent systems. Major research is concentrated on EMI mitigation for power converters in which the main concern is compliance with EMC standards to ensure proper operation of converters and nearby systems. This paper reviews EMI reduction techniques related to switching power converters with emphasis on the conducted EMI. A comprehensive review of significant research works is performed and various methods are thoroughly discussed and compared. Also, a classification of methods is presented. Moreover, converter prototypes are realized which contain several EMI mitigation techniques and their effects are presented via experimental results.

A Driving Scheme Using a Single Control Signal for a ZVT Voltage Driven Synchronous Buck Converter

Amin Asghari,Hosein Farzanehfard 전력전자학회 2014 JOURNAL OF POWER ELECTRONICS Vol.14 No.2

This paper deals with the optimization of the driving techniques for the ZVT synchronous buck converter proposed in [1]. Two new gate drive circuits are proposed to allow this converter to operate by only one control signal as a 12V voltage regulator module (VRM). Voltage-driven method is applied for the synchronous rectifier. In addition, the control signal drives the main and auxiliary switches by one driving circuit. Both of the circuits are supplied by the input voltage. As a result, no supply voltage is required. This approach decreases both the complexity and cost in converter hardware implementation and is suitable for practical applications. In addition, the proposed SR driving scheme can also be used for many high frequency resonant converters and some high frequency discontinuous current mode PWM circuits. The ZVT synchronous buck converter with new gate drive circuits is analyzed and the presented experimental results confirm the theoretical analysis.

A New Zero Voltage Transition Bridgeless PFC with Reduced Conduction Losses

Mohammad Mahdavi,Hosein Farzanehfard 전력전자학회 2009 JOURNAL OF POWER ELECTRONICS Vol.9 No.5

In this paper a new zero voltage transition PWM bridgeless PFC is introduced. The auxiliary circuit provides soft switching condition for all semiconductor devices. Also, in the resonant path of the auxiliary circuit, only two semiconductor devices exist. Therefore the resonant conduction losses are low. Furthermore, the auxiliary circuit semiconductor elements consist of only one diode and one switch. The proposed auxiliary circuit is applied to a bridgeless PFC converter to further reduce conduction and switching losses. In this paper, the operating modes of this converter are explained and the resulting ideal and simulation waveforms are shown. The presented experimental results justify the theoretical analysis.

A Fully Soft Switched Two Quadrant Bidirectional Soft Switching Converter for Ultra Capacitor Interface Circuits

Amin Mirzaei,Hosein Farzanehfard,Ehsan Adib,Awang Jusoh,Zainal Salam 전력전자학회 2011 JOURNAL OF POWER ELECTRONICS Vol.11 No.1

This paper describes a two quadrant bidirectional soft switching converter for ultra capacitor interface circuits. The total efficiency of the energy storage system in terms of size and cost can be increased by a combination of batteries and ultra capacitors. The required system energy is provided by a battery, while an ultra capacitor is used at high load power pulses. The ultra capacitor voltage changes during charge and discharge modes, therefore an interface circuit is required between the ultra capacitor and the battery. This interface circuit must have good efficiency while providing bidirectional power conversion to capture energy from regenerative braking, downhill driving and the protecting ultra capacitor from immediate discharge. In this paper a fully soft switched two quadrant bidirectional soft switching converter for ultra capacitor interface circuits is introduced and the elements of the converter are reduced considerably. In this paper, zero voltage transient (ZVT) and zero current transient (ZCT) techniques are applied to increase efficiency. The proposed converter acts as a ZCT Buck to charge the ultra capacitor. On the other hand, it acts as a ZVT Boost to discharge the ultra capacitor. A laboratory prototype converter is designed and realized for hybrid vehicle applications. The experimental results presented confirm the theoretical and simulation results.