Single-phase single-stage multifunctional grid interfaced solar photo-voltaic system under abnormal grid conditions

This study deals with a single-phase single-stage multifunctional grid interfaced solar photo-voltaic (SPV) system. The proposed SPV system is multifunctional as it has MPPT (maximum power point tracking) and it provides harmonics elimination, reactive power compensation and feeding SPV energy into the grid at unity power factor. The PV array is connected at the DC link of voltage source converter. The MPPT controller estimates reference PV voltage and a proportional integral controller is used to maintain the PV string voltage to the reference value. Feed-forward terms are used for SPV array and load components for fast dynamic response. The performance of the system is analysed under abnormal grid (sudden sag and swell) conditions. Simulation studies are performed on MATLAB-based platform. Simulation results are verified experimentally on a developed SPV system. Under steady-state operating conditions, the total harmonic distortion of grid voltage and currents are found well under IEEE-519 standard. A wide range of simulation and experimental results are presented to demonstrate all the features of the proposed SPV system.