A Single-Phase Transformer-less Five-Level Inverter Based on DC Decoupling with Reduced Leakage Current

In this article, a single-phase transformer-less five-level $(\mathbf{1}- \phi \mathbf{TL}\mathbf{5}\mathbf{L})$ inverter topology based on DC decoupling is proposes. Where PV is decoupled or disconnected from the rest of the system in a zero voltage state. Due to decoupling in the zero state, the common mode voltage retains the voltage of the prior state. As a result, the leakage current is decreased. The principles of common mode voltage (CMV) and leakage current are presented step by step. Furthermore, the working mode and switching state are well described. To understand the behavior of the proposed inverter, steady-state and dynamic-state tests are also performed. It is observed that the dc-link capacitors are well-balanced in both steady-state and dynamic-state conditions. To demonstrate the effectiveness of the proposed topology, the simulation results are presented.