Charge-based zero-voltage switching of a flying capacitor resonant pole inverter with trapezoidal filter current

Abstract

An advanced charge-based Zero-Voltage Switching (ZVS) modulation strategy for a Flying Capacitor Resonant Pole Inverter (FC RPI) with trapezoidal filter current is presented, resulting in full operating range ZVS, decreased rms value of the circulating filter current, and increased switching frequency. A charge-based model that correctly incorporates the nonlinear parasitic output capacitances of the switches is used to ensure ZVS. Increased efficiency of the multilevel RPI configuration is achieved due to minimized rms and peak value of the circulating filter current. Interleaving of multiple switching cells using simple phase control to increase the apparent switching frequency and lower the stress on filter components is investigated. The presented modulation strategy is verified using simulations from which proper operation is concluded