LVRT capability enhancement of single-phase grid connected PV array with coupled supercapacitor

Abstract

The penetration level of Photovoltaic (PV) systems in electrical grid is exceeding by a steep rate. This leads to increased vulnerability of electrical grid. Therefore, LVRT capability of PV systems has the utmost importance in term of future grid reliability. The LVRT capability of single phase inverters has been investigated in previous studies, but none of the prior investigations considered fault effects on DC side dynamics. The main contribution of this paper is to fill this gap so, in this paper grid fault effect on DC side voltage of inverter and MPPT algorithm is explored. Different reactive power injection strategies and their performance in term of the level of injected power fluctuation explored. The single phase connected PV array with supercapacitor and its control strategy proposed. Finally, the effectiveness of the proposed structure is validated by simulation carried out in MATLAB Simulink. The simulation results confirm the validity of the proposed approach.