Enhancing Power Quality in PV-DVR System: An MTOCF Approach for Imbalance and Distortion Mitigation

This article deals with a modified third-order complex filter (MTOCF) control technique for photovoltaic-based dynamic voltage restorer (PV-DVR). The photovoltaic (PV) array generates the active power and delivers it to the load. The voltage source converter (VSC) operates as a dynamic voltage restorer (DVR) and improves the power quality (PQ) of the grid by mitigating voltage imbalance and distortions. The existing TOCF-based control fails under weak grid scenario like dc offset conditions. This issue can be overcome by adopting a modified TOCF-based reference voltage algorithm. The prime motto of this work is suppression of lower order harmonics and elimination of dc offset using the developed MTOCF-based control. In addition, the extraction of positive sequence components from imbalanced voltages is explored. The algorithm has been tested under different scenarios, which includes normal grid conditions and voltage disturbances during day and night. The efficacy of the aforementioned control algorithm at various dynamic conditions is demonstrated using MATLAB/Simulink. A laboratory prototype of the same is developed and implemented using a generic 32-bit ARM Cortex-M4 Microcontroller (STM32F407VG) platform. The experimental results are in accordance with the simulation results, proving the effectiveness of the control algorithm.