Control of Grid Fed PV Generation using IIR Peak Filter in Distribution System

Abstract

This paper provides a control structure for a grid fed single stage photovoltaic (PV) array system. The PV array is utilized at maximum power through maximum power point tracking (MPPT) technique namely perturb and observe (P&O) algorithm. The solar array is used to feed to the grid via a voltage source converter (VSC) for transfer of power to the grid and the load in a distribution system. In addition, it also provides compensation of reactive power and elimination of harmonics. With the utilization of proportional integral (PI) control, the voltage level across the DC link of VSC is sustained at the reference voltage obtained from the MPPT. A digital infinite impulse response (IIR) peak filter is used for control of VSC by the extraction of load current fundamental component and generation of switching pulses of VSC. A feed-forward PV power term is incorporated for improvement of dynamic behavior of the system. A prototype of the system is developed in the laboratory and its performance is studied for varying load and solar insolation conditions.