Design and Optimization of Ac-side Filter using Coupled Inductor for Single-phase Full-bridge Inverter

This paper generalizes the design of ac-side filter using both coupled and non-coupled inductors for the single-phase full-bridge inverter. The relationship between the filter performance and the ratio of coupled and non-coupled inductance is derived and validated. By sweeping the ratio of inductance, the tradeoffs among weight, EMI attenuation, and loss are discussed. The study also demonstrates a holistic optimization of the filter for a 4.5 kW GaN-based single-phase inverter. Two designs were implemented, tested, and compared in the inverter prototype.