A New Common Ground Single-Phase Transformerless Five-Level Inverter for Photovoltaic Applications

The paper presents a new common ground single-phase transformerless five-level inverter for Photovoltaic (PV) applications. The topology is built with a minimum of six switches and three capacitors compared to various five-level inverter proposed in the literature and has the advantage of 100% dc-link utilization. The topology has the capability to supply both real power and reactive power. In order to achieve this, a simple level-shifted pulse width modulation scheme is used and proportional-resonant (PR) controller is developed to study the dynamic response of the system under input voltage as well as grid current changes. The performance of the proposed topology and their control scheme is validated through MATLAB simulation results. Finally, a detailed comparison is made with the recent five-level inverter topologies to highlight the merits of the proposed topolozy.