Single-phase transformerless nine-level inverter with voltage boosting ability for PV fed AC microgrid applications

Abstract

This letter presents a new single-stage common ground type nine-level (9L) switched-capacitor inverter topology with single-phase operation. The primary objective of this topology is to reduce the leakage current, voltage boosting, and maintain the voltage across the switched capacitors. The output voltage (v_o) can be boosted up to two times the input voltage (v_in). The various modes of operations are explained in detail, and the simulation results are provided to illustrate the effectiveness of the proposed topology. Next, the experimental results are obtained from a 500 W prototype setup and tested under different scenarios such as load variations, input voltage, and modulation index. Both simulation and experimental results have a good agreement regarding efficiency and performance. Finally, a detailed comparative study is performed with other recent 9L switched-capacitor inverters to prove the merits of the proposed topology.