摘要： This paper presents a robust extended complex Kalman Filter (RECKF) based control for multifunctional double stage grid-connected solar photovoltaic array (SPVA) system. The main contributions of presented paper, include: 1) real power generation from SPVA fulfils the requirement of the connected loads and it provides the surplus power to the distribution network, 2) it behaves as a distribution static compensator, which performs various functionalities such as grid currents balancing, harmonics mitigation, unity power factor operation, 3) it is capable to operate under polluted grid scenarios such as under voltage, over voltage and imbalanced grid voltages. The SPVA feed-forward term is incorporated in the control technique to enhance the dynamic response of the system. The real coded particle swarm optimization (RCPSO) based metaheuristic approach is used for optimal tuning of the DC link voltage PI (Proportional Integral) controller. Simulation results illustrate the effectiveness of presented control algorithm under variations in point of common coupling (PCC) voltage. Test results illustrate the behaviour of grid-connected SPVA system subjected to various perturbations such as under voltages, over voltages, distorted and imbalanced grid voltages etc. The THDs (Total Harmonic Distortions) of grid currents are achieved well within recommended limits.