Three‐phase Rectifier with Minimum Voltage Active‐clamping Circuit

This chapter introduces a zero‐voltage‐switching (ZVS) three‐phase rectifier with minimum voltage active clamping (MVAC) circuit, including the operation principle, the circuit analysis, and the design guidelines of the MVAC rectifier. It also introduces the operation principle of the ZVS‐space‐vector‐modulation scheme, and aims to derive the soft‐switching condition. There are two resonant stages in a switching cycle. The first one realizes ZVS turn‐on for the bridge switches and the second one realizes the ZVS turn‐on for the auxiliary switch. When the rectifier is operated in steady state, the mean voltage of the resonant inductor in a switching cycle is zero. The chapter provides the operation principles of the proposed ZVS rectifier and the modulation scheme. MVAC rectifier can realize ZVS operation for all switching devices, and the antiparallel diode reverse recovery current of all switch devices is suppressed well. The chapter discusses a design example of a 30 kW MVAC rectifier prototype.