Solar PV Array Integrated UPQC for Power Quality Improvement Based on Modified GI

Abstract

In this paper, a modified generalized integrator (GI) control technique with a reduced number of integrators, is presented for the control of grid interfaced single stage solar PV array integrating with unified power quality conditioner (SPVA-UPQC) system. This controller has a reduced number of integrators to estimate the fundamental active components of the distorted signals enabling DC offset elimination. Further, these fundamental signals are used to generate the reference signals for shunt compensator. The SPVA-UPQC helps to mitigate both current and voltage related power quality (PQ) problems such as it eliminates harmonics, load unbalancing, reactive power compensation, voltage sag-swell elimination, as well as it provides clean energy generation, by interfacing solar PV array at the common DC link of UPQC. In order to evaluate the performance of this system with presence of nonlinear load, simulation results are presented in environment of MATLAB/Simulink. The experimental performance of the SPVA-UPQC system is validated through developed prototype and the corresponding results are presented herein for various conditions like grid voltage sag, grid voltage swell, load unbalancing, solar irradiation variation and harmonics. The total harmonic distortion (THD) of the grid voltages and currents are attained within the limits as per the IEEE-519 and IEEE-1159 standards.