Modulation method for single-phase six-switch five-level ANPC inverter

The Five-Level Active-Neutral-Point-Clamped (5L-ANPC) inverter is one of the most popular topologies among five-level inverters since it combines the features of Flying-Capacitor (FC) type and Neutral-Point-Clamped (NPC) type inverters and was commercially used for industrial applications. This paper proposes a novel modulation strategy for a Six-Switch 5L-ANPC (6S-5L-ANPC) topology to keep voltages of DC-link capacitors and FC balanced. The equations to calculate the FC capacitance in active and reactive power conditions are also provided. Simulation and experiment have been carried out to demonstrate the effectiveness of the proposed modulation technique.