New low-cost five-level active neutral-point clamped converter

Multilevel converters are a popular solution for medium-voltage and high-power applications, including renewable energy conversion. Five-level active neutral-point-clamped converter (5L-ANPC) is one of the most advantageous topologies among five-level multilevel converters. A six-switch 5L-ANPC (6S-5L-ANPC) topology is proposed, which can achieve low-cost because several fast recovery diodes are employed to replace the body-diodes and active switches. However, the power branches including the diode can only provide active current path. Special modulation strategy is proposed to achieve reactive power operation. The simulation analysis shows the proposed 6S-5L-ANPC is suitable for unity power factor application such as photovoltaic (PV) application. A 500W single-phase inverter prototype is built to verify the validity and flexibility of proposed topology and modulation.