Analysis of electromagnetic processes in AC-DC converters with possibility of reverse flow of energy and increased efficiency

The paper considers the questions of energy transfer in a charge/discharge autonomous power supply device. Power circuit of considered charge/discharge device is based on the scheme of reversing up/down converter with the switching mode of power transistors at zero-voltage that ensures high efficiency of device. In the course of analysis of electromagnetic processes in the converter, mathematical expressions that describe the transfer of energy, from the side one to the side two of the reversible converter have been obtained. Using the obtained mathematical expressions, a method and algorithm for calculating RMS current through elements of the power converter circuit using parameters of the power circuit elements and parameters of energy transformation, in particular, using reverse displacement current of a choke, providing switching mode of power transistors at zero voltage have been developed. Correlation between RMS current through a choke and power transistors, and value of reverse replacement current of a choke for a number of modes are given graphically. All correlations were obtained at fixed power at the side two and variation of voltage value at the side one of converter. Analysis of obtained correlations has shown growth of RMS current through power circuit elements of the converter at increasing reverse displacement current of a choke, which corresponds the theoretical requirement. Developed method, algorithm and program for the calculation of RMS current through elements of the power circuit of converter can be used for solving design problems of the charge/discharge device which based on the scheme of reversing up/down converter with the switching mode of power transistors at zero-voltage, and for solving the problem of minimizing the total static and dynamic energy losses in the converter.