Jaroslav Dudrik

Soft-Switching PS-PWM DC–DC Converter for Full-Load Range Applications

An improved soft-switching full-bridge phase-shifted pulsewidth modulation converter using insulated-gate bipolar transistors with a special auxiliary transformer is presented in this paper. Zero-voltage switching for leading leg and zero-current switching for lagging leg switches in the converter are achieved for full-load range from no load to short circuit by adding an active energy recovery clamp and auxiliary circuits. The new significant feature of the converter consists in suppression of circulating current also in short-circuit conditions. The proposed converter is very attractive for applications where short circuit and no load are the normal states of the converter operation, e.g., arc welding. The principle of operation is explained and analyzed, and experimental results are presented on a 3-kW 50-kHz laboratory converter model.

Zero-Voltage and Zero-Current Switching Full-Bridge DC–DC Converter With Auxiliary Transformer

A novel zero-voltage and zero-current switching (ZVZCS) full-bridge phase-shifted pulsewidth modulation (PWM) converter using insulated gate bipolar transistors (IGBTs) with auxiliary transformer is proposed to improve the properties of the previously presented converters. ZVZCS for all power switches is achieved for full load range from no-load to short circuit by adding active energy recovery snubber and auxiliary circuits. The principle of operation is explained and analyzed and experimental results are presented. The features and design considerations of the converter are verified on a 3-kW, 50-kHz IGBT based experimental circuit

Soft-Switching Full-Bridge PWM DC–DC Converter With Controlled Output Rectifier and Secondary Energy Recovery Turn-Off Snubber

A zero-voltage and zero-current switching full-bridge pulse-width modulated dc-dc converter with controlled secondary-side rectifier using a novel nondissipative energy recovery turn-off snubber is presented in this paper. Using a controlled rectifier, a turn-off snubber, and an innovative control algorithm, the circulating current of the converter is eliminated and soft switching for all power switches of the inverter is achieved for full-load range from no-load to short circuit. The principle of converter operation is explained and analyzed and the experimental results on a 4.5 kW, 100 kHz laboratory model of the converter are presented.

Bi-directional DC/DC converter for hybrid battery

Bi-directional buck-boost DC/DC converter for hybrid battery controlled by UC3637 is described in this paper. The first part of the paper is aimed at concept of hybrid battery. Design of power circuit and control circuit with UC3637 of converter is described in the second part of the paper.

Voltage fed zero-voltage zero-current switching PWM DC-DC converter

A new zero-voltage zero-current switching full-bridge phase-shifted PWM converter with controlled output rectifier is presented in this paper. IGBT switches are used in the high-frequency inverter of the DC-DC converter. Zero-voltage turn-on and zero-current turn-off for all power switches of the inverter is achieved for full load range from no-load to short circuit by using new secondary energy recovery clamp and modified PWM control strategy. Moreover by adding energy recovery clamp the zero-current turn-on and zero-voltage turn-off for rectifier switch is ensured. The principle of operation is explained and analysed and simulation results are presented.

Considerations on the analysis of an induction heating system

This paper presents some considerations on the analysis of an induction heating system and problems that arise during the heating process of steel pieces. The steel pieces under the heating process are modeled to be used as electrical circuit elements of the heating system load. The model of the steel pieces under the heating process consists of a resistive - inductive circuit in order to underline the resistive and inductive effect of the load that influences the thermal process. Using this approach, the whole system is presented as a power electronic one in order to assure a generalized model that can be used further to develop control strategies or to optimize the heating process. A class D series resonant inverter was chosen to assure a high efficiency of the electrical energy conversion. The inverter is accomplished with power MOSFETs that allow high operation frequency of the heating installation. Using the high frequency operation, tens of kilohertz, the system offers the possibility to make even a surface heating of the steel pieces. To model the induction heating system, two simulation software were used: FLUX 2D and MATLAB. First simulation software was used to describe in time the electro thermal behavior of the load and the second simulation program was used to model the induction heating system seen as a whole. This analysis is useful in the designing of induction heating installations and the evaluation of their operation.

Zero-voltage and zero-current switching DC-DC converter with controlled output rectifier

A full-bridge PWM DC/DC converter with controlled output rectifier is presented in this paper. Soft switching for all power switches is achieved by using controlled output rectifier with new lossless energy recovery turn-off snubber on the secondary side of the converter. No circulating current is occurred in the proposed converter with used new control method. The principle of operation is explained and analyzed and the experimental results on a 1.2kW, 50 kHz laboratory model of the converter are presented.

Soft-Switching PWM DC-DC Converter for High Power Applications

Soft switching full-bridge phase-shifted PWM converter using IGBTs with auxiliary transformer is presented in this paper. Zero-voltage and zero-current switching for all power switches is achieved for full load range from no-load to short circuit by adding active energy recovery snubber and auxiliary circuits. The principle of operation is explained and analysed and experimental results are presented. The properties of the converter are verified on a laboratory model

Novel soft switching DC/DC converter with controlled output rectifier

A novel full-bridge PWM DC/DC converter with controlled secondary side rectifier using secondary snubber is presented in this paper. Circulating current of the converter was eliminated and soft switching for all power switches of the inverter is achieved for full load range from no-load to short circuit by using controlled rectifier and snubber on the secondary side. The principle of operation is explained and analyzed and the experimental results on a 4,5kW, 100 kHz laboratory model of the converter are presented.

Zero-Voltage and Zero-Current Switching PWM DC–DC Converter Using Controlled Secondary Rectifier With One Active Switch and Nondissipative Turn-Off Snubber

Soft switching pulse-width modulation (PWM) dc–dc full-bridge converter with controlled rectifier on the secondary side of the high-frequency power transformer is presented in this paper. An active secondary switch, including new nondissipative passive energy recovery turn-off snubber on the secondary side and modified PWM control algorithm, provide conditions for zero-voltage and zero-current turn-on and zero-current turn-off of IGBT transistors on the primary side of the high-frequency dc–dc converter. The simple passive energy recovery snubber ensures also zero-voltage turn-off of the transistor on the secondary side of the power transformer. The principle of operation is explained and analyzed and consequently verified on a 2 kW, 50 kHz laboratory model of the converter.