Combined PDM and Synchronous Time-Pulse Control Method with Continuous Regulation and Equalization of Losses in IGBT of Series Resonant Inverter

A combined control method of pulse-density modulation and synchronous pulse-time modulation (PDM-STPM) for a bridge voltage inverter with a series resonant circuit (SRI) is proposed, which provides continuous regulation with distribution of control pulses, energy circulation and equalization of power losses in IGBT (MOSFET) HB-module to improve output power factor and efficiency. An analytical model of SRI controlled by the combined PDM-STPM method proposed is developed. The model makes it possible to investigate its effectiveness when the output power is changing, the quality factor of the oscillatory circuit, and switching frequency, taking into account real characteristics of power modules (IGBT, MOSFET).According to the results of analytical modeling of SRI with an output power of 40 kW and a resonant frequency of 100 kHz, the increase in efficiency when controlling with the combined PDM-STPM method compared to the STPM method is on average 4.5% (from 1.5% at γ=0.875 to 7.6% at γ=0.25).