Direct decoupled active and reactive predictive power control of grid-tied Quasi-Z-Source inverter for photovoltaic applications

This paper proposes a decoupled power control algorithm for grid integration of photovoltaic (PV) systems using quasi-Z-source inverter (qZSI). The proposed controller uses model predictive control (MPC) framework to inject the maximum available power harvested from the PV panels to the grid and also to compensate reactive power required by the grid. Thus, a power electronics interface (PEI) is proposed to integrate the PV panels to the grid and also to work as a reactive power compensator simultaneously. A reliable technique is proposed to regulate the impedance network elements' voltage and current according to the maximum operating point of PV panels and grid voltage/current requirements. The proposed controller features simple structure for practical implementation, fast dynamic response under changing sky condition, and negligible tracking error in steady state condition for decoupled active and reactive power control in a typical distributed generation (DG) systems. The performance of the proposed controller is verified experimentally using dSPACE DS1007 platform, and the grid-side power quality analysis is provided and evaluated according to IEEE-519 standard.