A hybrid active and reactive power control with Quasi Z-source inverter in single-phase grid-connected PV systems

Abstract

This paper presents a hybrid method of active power and reactive power control strategy with Quasi Z-source inverter (QZSI) in single phase grid connected photovoltaic (PV) systems. The maximum power from the PV panel is extracted and most of it is supplied as active power to the grid. The major portion of required reactive power exchange to the grid is done by means of thyristor switched capacitor (TSC) and thyristor switched reactor (TSR) to improve the generation capacity of the PV system. In the proposed topology inverter shares the minimum reactive power and large change in reactive power will be delivered/absorbed by the TSC-TSR to get smoother operation in reactive power control. The DC voltage controller and the AC current controller is discussed in brief. The mathematical analysis for grid synchronization method is presented in detail. The control algorithm for active power and reactive power is analyzed and discussed in the paper. The simulation results are shown for validating the proposed concept.