Effects of circuit nonlinearities on dynamic dead time optimization for a three-phase microinverter

This paper investigates the effect of circuit component nonlinearities on dead time optimization for a three-phase microinverter with a peak current mode zero voltage switching (ZVS) output stage. The primary nonlinearities are those associated with MOSFET and other switching devices parasitic capacitance which may vary significantly as a function of the device operating voltage. In addition, filter inductor values vary as a function of operating current. The effect of the dynamic nature of these circuit components on inverter efficiency and dead time optimization is analyzed. Both calculated and experimental results are obtained using a 400-W three-phase half-bridge microinverter prototype.