250W GaN Hybrid BCM Micro-inverter Design for Avionic Applications

In this paper, a GaN based zero voltage switching hybrid boundary conduction modulation (BCM) micro-inverter is analyzed, simulated and designed for avionic applications. The soft switching is realized by the inductor current resonating with the switches' output parasitic capacitances thereby eliminating the need for extra power devices or magnetic components use. Hybrid BCM method enables micro-inverter control by taking advantage of the digital signal processor (DSP) and analog circuitry resources. Operation principle, simulation, layout considerations and experimental results are presented in this paper. In accordance with the avionic requirements, 270 vdc input and 115 Vac400 Hz at the output, 250 W single-phase full-bridge micro-inverter prototype with the latest released GaN switches was built. The experimental result demonstrates that high efficiency for wide power range is achieved using latest released GaN switches and hybrid BCM control. This paper demonstrates that designed BCM controlled micro-inverter reaches 96.9% peak efficiency reducing the space needed for a cooling system. The reduced weight and volume of the micro-inverter contributes optimum flight time and better mission performance to military aerial vehicle.