Design a passive filter in combination with SAPF to improve the power quality of the solar hybrid micro-grid system and combustion engines

Excessive voltage harmonic distortion in distribution grids is a major power quality disturbance that negatively impacts micro-grids. The rise of contemporary industry and the expansion of power electronics in the grid contribute significantly to these harmonic distortions. Consequently, harmonic analysis of distribution networks is essential. This paper examines the implementation of an LR–CR passive filter combined with a series active power filter (SAPF) and Buck converter topology to mitigate harmonics generated by power electronic devices in a hybrid micro-grid system. This system includes nonlinear loads, energy storage, wind turbines, and solar cells. A sample harmonic micro-grid is developed in the MATLAB/Simulink environment, operating in both grid-connected and islanded modes, to collect data for designing the passive filter. To enhance power quality, a hybrid filter combining a passive filter and a SAPF is employed to reduce both higher-order and lower-order harmonics. The design results in specific filter parameter values. Simulation results from MATLAB/Simulink confirm the efficiency of the passive filters in improving micro-grid power quality indices and the performance of combustion engines. Our main findings are: • Hybrid filter with SAPF improves solar hybrid micro-grid power quality, reducing THD to 0.11%. • Enhances power factor and voltage stability, mitigating harmonic distortion's impact. • Offers cost-effective, reliable solution for improving solar micro-grid performance. Simulation results demonstrate a THD reduction to 0.11% (98.2% improvement), power factor enhancement to 0.98, and 95% mitigation of voltage sags during faults.