Grid coupled maximum power point tracked photovoltaic system with selective power conditioning capability

Varying insolation often leave the grid coupled Photovoltaic (PV) systems with partly unutilized power capacity of voltage source converter (VSC). In this paper, an improved method based on current decomposition for reference generation and therefore its indirect control is presented for better utilization of hardware. The proposed control also ensures complete evacuation of maximum tracked power point (MPP) tracked power by regulating the current at DC bus. For maximum power evacuation from the PV array maximum power point tracking (MPPT) technique based on Incremental Conductance (IC) method is used. The unutilized capacity of the grid coupled VSC besides maximum power evacuation from the PV array is used for selective and limited power conditioning determined by the proposed algorithm. Synchronous reference frame (SRF) theory base current decomposition is used for determining the limited compensation to be provided by the grid coupled VSC, based on its unutilized capacity. Based on severity of the problems at the load side selective and priority based compensation may also be provided. Simulation based result demonstrate that proposed method provide effective compensation for different types of load along with full PV power evacuation. MATLAB based simulation results also show that efficient working of the MPPT algorithm under fast changing insolation conditions.