Soft‐switching SiC Single‐phase Grid Inverter with Active Power Decoupling

This chapter introduces the soft‐switching technique to single‐phase grid inverter with active power decoupling (APD). It also introduces commonly used modulation methods for single‐phase inverter and the basic concept of APD. For the conventional hard‐switching single‐phase inverter, there are three commonly used modulation strategies: unipolar sinusoidal pulse width modulation (SPWM), bipolar SPWM, and unipolar double‐frequency SPWM. The chapter provides the detailed operation principle of the inverter, and analyzes soft‐switching condition. It discusses zero voltage switching (ZVS) condition of the inverter based on state equations. The chapter also presents the prototype design of a 1.5‐kW silicon carbide metal‐oxide ‐semiconductor field effect transistor soft‐switching inverter. A 1.5‐kW inverter prototype is designed to verify the theoretical analysis. Experiment shows that the double line frequency ripple of DC input current is greatly reduced, and ZVS of all switches are realized.