A zero‐current‐transition soft‐switching technique for T‐type NPC three‐level inverter

Based on the commutation property of T-type neutral point clamped (T-NPC) three-level inverter, a novel zero-current-transition (ZCT) soft-switching topology is proposed. The proposed employs only two auxiliary switches and one inductor capacitor (LC) resonant tank each phase leg. process technique analyzed. results show that all main leg can achieve soft without changing pulse width modulation (PWM) strategy. control family T-NPC ZCT are analyzed respectively, then timing schemes different modes given. Using in resonance produce greater current due to combination external excitation sources, which more conducive realize switch. At last, half bridge prototype inverter built. influence equivalent internal resistance power switches, diode reverse recovery stray inductance for advantages technology verified.