A high power density grid connected soft switched inverter

This paper proposes a new ZVS technique for full-bridge single-phase inverters that has several applications such as PV ac modules. The technique uses smaller passive filter between inverter and grid which results in a simple control, simpler design and a more compact and more efficient topology. The proposed topology uses a passive LC small auxiliary circuit which operates under fixed frequency and leads to a simpler EMI filter design. Using the proposed topology, the switching frequency can be increased to achieve smaller size and higher efficiency inverters. A controller to minimize conduction loss in the auxiliary circuit is designed and analysis, simulation and experimental results are also provided to verify the theory.