Linear current control technique for grid connected photovoltaic system

The employment of power converters to integrate renewable energy sources to the utility network is well known. In such context, there is an increasing interest in developing an appropriate control methodology to ensure perfect compliance of photovoltaic systems with the utility by obtaining a current with low harmonic distortion. In this paper a current control strategy for grid connected photovoltaic inverter via LCL filter has been proposed. In this control system three linear voltage and current controllers were used in a cascade disposition in order to reduce the complexity of the system. Those controllers are designed in a synchronous reference frame which transforms ac variables into dc quantities, and regulate the current injected to the grid. Simulation results, using Matlab/Simulink, presented for this approach confirm the effectiveness of the control scheme in both transient and steady state operation.