Errors in the analysis of series resonant inverter/converter assuming sinusoidal waveforms of voltage and current

In this paper the theory and simulation results of the series resonant inverter / converter are presented. In this work the authors carried out a detailed comparative analysis of results obtained using the method of AC analysis in the steady state for the first harmonic with the results of computer simulation. The AC analysis under certain conditions can lead to errors disqualifying this method. In particular, these errors appear by low quality factor of resonant circuit, pulsed, discontinuous load current, switching frequency significantly different from the resonance. It was also shown that the coefficient for transforming the resistor behind the rectifier into the equivalent resistor in AC circuit may vary substantially from the values known from the literature.