Performance of a grid-connected solar PV system using class D chopper

Abstract

Due to the increasing demand for clean energy, the grid-connected photovoltaic (PV) generation system is expected to be more world widespread. However, to ensure an efficient PV-grid-integration system a good interface system between the grid and the PV is always needed. In this work, a power electronic interface using a class D chopper is proposed and its performance is investigated. Actually, in this work, the conventional DC-DC buck converter is replaced by a class D chopper circuitry. It controls the power transfer and helps better utilizing maximum power that can be obtained from the PV array at any possible surrounding weather conditions. The class D chopper semiconductor switches are controlled through the widely used Perturb and Observe (P&O) control technique with the help of the on/off controller having a hysteresis characteristic. The computer simulation results demonstrated the effectiveness of the proposed power electronic interface but it revealed deterioration of the quality of the current waveform drawn from the grid as well as the absorption of reactive power from the grid. Such additional reactive power resulted in lowering power factor levels. To overcome such undesirable facts, the interface system has been enhanced by adding a shunt power setup attributed in this article to the name: Power Quality Conditioner (PQC). In doing so, the updated simulation results showed that the enhanced interface system achieved very satisfactory results in terms of harmonics currents levels reduction and positive reactive power compensation at the expense of noting a negligible effect on active power generated from the grid-PV system.