Design of a Photovoltaic Grid-Tied Inverter Employing a Dual-Stage Boost Converter and a Transformer-Less Step-Down Circuit
In this paper the authors propose a topology for a transformer-less, pure sine wave Grid-Tie Inverter (GTI) for PhotoVoltaic (PV) application. The proposed GTI employs a dual-stage boost converter, a transformer-less step down circuit, an H-bridge inverter and a T-LCL Immittance conversion circuit. The switching technique of the proposed inverter consists of a combination of Sinusoidal Pulse Width Modulation (SPWM) and a square wave along with grid synchronizing conditions. As the suggested method is entirely transformer-less, it significantly reduces the Total Harmonic Distortion (THD) of the output voltage (less than 0.1%), minimizes its size and swells the inverter efficiency up to 97%.