Comparative Study of Line Frequency and Combined Lineffligh Frequency Control in a Single Stage DC-AC Converter

Single stage DC-AC converter with sinusoidal phase shifted full bridge converter as the front end followed by cycloconverter is commonly used for microgrid/EV applications. The operation and analysis of the converter with cycloconverter switching at line frequency and combined line/high frequency are presented in this paper. The control configuration implementation for single stage DC-AC converter with a sinusoidal phase shifted front end followed by a cycloconverter is presented which ensures soft transitions for all the semiconductor devices. The comparison of line frequency switching and combined line/high frequency switching of cycloconverter devices of single stage DC-AC converter in terms of performance and efficiency is presented. Analytical expressions for the computation of losses in the cycloconverter switched at line frequency and combined line/high frequency are proposed. The control, analysis, and mathematical expressions are verified in simulations and 500 W single stage DC-AC converter experimental prototype.