Delta-sigma modulated class D ZCS series resonant inverter with an inductive load

Applying the delta-sigma modulated driving patterns, Class D zero-current-switching (ZCS) series resonant inverter driven at 200 kHz outputs the 50-Hz sinusoidal envelope waveform. In this study, the load impedance which was limited to a purely resistive load is expanded to an inductive load. The waveforms observed in experiments and simulations have well agreed. The Class D inverter outputs the 50-Hz sinusoidal envelope waveform with maintaining ZCS under the condition of an inductive load. The measured power conversion efficiency was 70.2% at the switching frequency 193 kHz, 2.6 W in reduced- scale circuit experiments.