Performance analysis of grid connected solar photo-voltaic system under grid abnormal conditions

This work deals with a single phase single stage multifunctional grid interfaced solar photovoltaic (SPV) system. The single stage topology utilized in the grid connected PV system has the advantages of high efficiency and low cost compared with the two stage topology the primary function of the grid connected inverter in a single stage SPV system is to supply active power into load and grid. The added functions to the grid connected inverter are compensation for reactive power requirements and mitigation of the harmonics produced by the nonlinear loads connected at the point of grid connection. A hill climbing MPPT controller is used for tracking the maximum power from photovoltaic array under grid abnormal conditions. The PV array is connected to voltage source converter (VSC) through DC link. The MPPT controller estimates reference PV voltage and corresponding PV power. A PLL-less control [3] is used for control of multifunctional VSC. The voltage source converter (VSC) controller uses the load and PV forward terms for fast dynamic response. The performance of the SPV system is analyzed under grid abnormal conditions (sudden sag and swell). The simulation studies are performed on MATLAB/SIMULINK.