Abstract
This paper addresses the problem of improving power quality in a microgrid that integrates renewable energy sources, specifically wind energy systems (WES) and photovoltaic (PV) installations, through the application of an LC filter at the output of an inverter-based distributed generation unit. The study examines the fundamental physical principles of LC filter operation, including its frequency response characteristics and its role in mitigating high-frequency harmonics generated by power electronic converters. Special attention is given to the influence of the LC filter on the overall stability and dynamic performance of the microgrid under varying load conditions. An engineering design and calculation of LC filter parameters are carried out for a 220 V microgrid with a rated power of 3 kW and a pulse-width modulation (PWM) frequency of 10 kHz. The results demonstrate that appropriately designed filter parameters ensure attenuation of high-frequency harmonics exceeding 50 dB, significantly reducing the total harmonic distortion (THD) of the output voltage. Furthermore, the proposed approach contributes to improved voltage waveform quality and enhanced reliability of the microgrid. The findings confirm the effectiveness and practical applicability of LC filters in distributed generation systems based on renewable energy sources.