Implementation of Voltage Imbalance Mitigation Using SOGI Based PV-DVR System
Sujitha Janardhanan, Mahmadasraf A. Mulla
Abstract
Due to the increase of non-linear loads in recent years, power quality issues have attracted more attention. One of the major power quality problems is an imbalance in grid voltages. The existing control strategy involving conventional Phase Lock Loop (PLL) for photovoltaic based dynamic voltage restorer (PV-DVR) can mitigate voltage sag/swell but fails to mitigate under grid voltage imbalance. This issue can be overcome by adopting second order generalized integrator (SOGI) based reference voltage algorithm. This research is mainly focused on the performance of the PV-DVR, by incorporating SOGI based control technique for the fundamental component extraction from the grid voltage to mitigate the imbalance. The extracted component is then utilized to generate reference load voltage and it ultimately improves the power quality of the grid voltage. The proposed algorithm also performs well under different scenarios, which includes normal grid condition and voltage imbalance during day and night time. The simulation studies conducted in MATLAB/Simulink proves the effectiveness of SOGI based PV-DVR. Using the generic 32-bit ARM Cortex-M4 Microcontroller (STM32F407VG) platform, a laboratory prototype of the same is developed and implemented. All simulation findings are verified by experimental results.