Five-Level Transformerless Common Ground Type Inverter with Reduced Device Count

Abstract

In recent days, the transformerless grid-connected PV inverter is paid more attention due to its compactness and high efficiency with low cost. This paper presents a new five-level transformerless switched capacitor type inverter with a reduced number of power components. The proposed topology has a lower number of power components with a common ground connection between the negative terminal of the input side and load that eliminates the leakage current. The switched capacitors do not require any sensors for their balancing. The different modes of operation and control of the PWM technique are discussed. The proposed topology is compared with recent transformerless inverters, and the advantages of the proposed topology are highlighted. The simulation and experimental results are presented. The prototype hardware setup is built for 1.2 kW and has the simulated maximum efficiency of 96.4%. The performance of the proposed topology is measured by applying various load and modulation index variations.