A New Six-Switch Five-Level Active Neutral Point Clamped Inverter for PV Applications

Abstract

Multilevel inverters are one of the preferred solutions for medium-voltage and high-power applications and have found successful industrial applications. Five-level active neutral point clamped inverter (5L-ANPC) is one of the most popular topologies among five-level inverters. A six-switch 5L-ANPC (6S-5L-ANPC) topology is proposed. Compared to the conventional 5L-ANPC inverters, the 6S-5L-ANPC reduces two active switches and has lower conduction loss. The proposed modulation enables the 6S-5L-ANPC inverter to operate under both active and reactive power conditions. The flying-capacitor capacitance is designed under both active and reactive power conditions. The analysis shows the proposed topology is suitable for photovoltaic grid-connected applications. A 1 KVA single-phase experimental prototype is built to verify the validity and flexibility of the proposed topology and modulation method.