Development of simple PWM inverter using photovoltaic cells

Abstract

This paper presents the development of a simple 1.5kW single-phase sinusoidal Pulse Width Modulation (PWM) inverter. This inverter is designed to be either a stand-alone or grid connected inverter from a direct supply of photovoltaic (PV) cells. The developed inverter unit converts the DC input supply from the PV cells into a clean sinusoidal voltage output. This power inverter is also capable to be a grid-connected PV system where the electricity produced by PV, which exceed the load consumption can be feed back to the grid. The inverter is of a full-bridge topology using a step-up transformer. The PWM signals, which feed the bridges, are generated by a dual ended PWM modulator, and isolated gate driver. The L-C filter is implement after the step-up transformer before the load to attenuate the harmonics component. The 1.5KW designed prototype of the inverter was tested with the resistive loads and a fluorescent lamp and the total harmonic distortion (THD) for all load is about 2.7%.