An Inverse Park Phase-Locked Loop based Control for Multifunctional Grid-Connected SPV System

Abstract

In this paper, a simple controller is designed based on Inverse Park Phase-Locked Loop (IPPLL) for a multifunctional grid-connected solar photovoltaic system. The proposed IP-PLL tracks the grid voltage signal to estimate phase and quadrature signal generation to estimate magnitude and similarly, IP-QSG to estimate magnitude of load current signal. Implementing this PLL improves the accuracy of tracking the signal and also has filtering capabilities which in-turn improves power quality such as reactive power compensation, harmonic rejection and proper feeding of SPV energy etc. Incremental Conductance (INC) based maximum power point tracking (MPPT) is used for estimating the reference PV voltage signal and power. The IP-PLL based algorithm performs well under change in irradiance, grid disturbances such as sag/swells and also under load perturbations. These multifunctional capabilities of the grid-connected SPV make the overall system to be more efficient. These operating conditions are tested in MATLAB/Simulink platform.