A Power Decoupling Technique for High Power-Density Single-Phase Inverters

Abstract

Replacing Electrolytic capacitors with durable Film types, improves reliability of a single-phase inverter at the ex-pense of degrading its power density. A method to compensate the double-frequency ripple for single-phase double-stage inverters is proposed that optimizes the size of the required capacitor and fur-ther improves the power density. This method partially removes the double-frequency ripple from the dc link and leaves the rest of the ripple uncompensated. Using this method, a natural-cooled 5kVA single-phase inverter with effective switching frequency of 240kHz is implemented based on Gallium Nitride ($GaN$) power switches. Simulation and experimental results verify the method's performance.