Analysis and design of single-phase T-type transformerless inverter for PV applications

In this paper, a Common Mode Voltage (CMV) analysis as well as efficiency analysis for T-type transformerless inverter is performed. In the CMV analysis, a modulation scheme is implemented which is suitable to keep the ground leakage current at zero. The efficiency analysis of the T-type inverter is performed with real models of the semiconductor devices using PSIM software. Based on the simulation results it is possible to demonstrate that the implemented modulation scheme achieves high efficiency, while the conduction and commutation losses of the bi-directional switches are kept in low values. Also, the implementation of a single-phase T-type transformer-less inverter for photovoltaic (PV) applications is presented in an experimental setup designed for 1.5 kW.