Comparison of Control Techniques for Series Resonant Converter

Abstract

There are many different derivatives of variable and fixed frequency switching control techniques used in control of load resonant converters. In this study; among these techniques frequency modulation (FM), phase shift modulation (PSM) and pulse density modulation (PDM) are applied separately to series resonant converter (SRC). The techniques are examined and compared in many respects. An experimental setup is built, which consists of a 400W converter, a control circuit and a resistive load to verify theoretical studies. The converter is controlled by FM, PSM and PDM separately for 120 kHz basic operating frequency and different output currents. Experimental results are compared in terms of efficiency, output voltage ripple, soft switching, switch voltage, ease of application and hardware. The comparison results are presented. Thus, effect of each technique on the operating parameters of the converter is revealed. Moreover, it is also observed that FM has better performance than the other two techniques in many aspects

Keywords

• resonant converters
• control techniques
• fm
• psm
• pdm