Power quality enhancement and DC offset rejection in PV-DVR system using ESOGI-based control

With the increasing penetration of renewable energy sources in the power grid, photovoltaic-based dynamic voltage restorer (PV-DVR) has emerged as an efficient and eco-friendly solution for improving voltage stability and power quality. The performance of PV-DVR depends on the accuracy of grid synchronization and harmonic component extraction in the grid voltage. The traditional control technique based on SOGI-PLL works well under balanced voltage sag/swell and unbalance conditions. However, SOGI-PLL fails in mitigating the DC offset and harmonics. This article is mainly focused on the performance of the PV-DVR, by incorporating enhanced second-order generalized integrator (ESOGI)-based control technique for the fundamental component extraction from the grid voltages to mitigate the unbalance, DC offset and distortion. The proposed algorithm also performs well under weak grid scenario such as voltage sag/swell. The ESOGI-based control is utilized to generate reference load voltages for controlling the voltage source converter and improves the power quality of the grid voltage. The algorithm tested across a range of scenarios, including normal grid conditions, voltage sag/swell, voltage unbalance and voltage distortion occurring during both daytime and nighttime. The simulation studies conducted in MATLAB/Simulink prove the effectiveness of ESOGI-based PV-DVR system.