A Novel Two-Stage Hybrid T-type Five-Level Transformerless Inverter

Abstract

This paper presents a new two-stage hybrid T type five-level inverter for 1-φ grid connected photovoltaic applications (PV). The new topology comprises three-level boost converter (3LBC) and hybrid T-type five-level inverter. The 3LBC balances the capacitor voltages by employing simple control algorithm and also improves power conversion efficiency by lowering voltage stress. The sinusoidal level shifted pulse width modulation (SLS-PWM) scheme is used to operate the inverter at different power factor conditions without affecting the transitions in common mode voltage (CMV). Moreover, the leakage current produced by the parasitic capacitance of the PV panel is minimized by providing common mode path to the inverter. Furthermore, it also minimizes the voltage rating of the power semiconductor switches, total harmonic distortion and the filter size. Simulation results are presented to validate the capabilities of the proposed inverter.