Active Power Filters For Power Quality Enhancement In Microgrid Due To Renewable Energy Integration: A Review

Abstract

The rising energy demand in residential and industrial sectors has accelerated the deployment of distributed generationsystems,particularly photovoltaic (PV) and wind energy conversion systems (WECS). While these renewable sources offer environmentalandeconomic benefits, their grid integration introduces power quality challenges such as harmonic distortion, reactive power imbalance,voltage fluctuations, and switching losses associated with power electronic converters. These issues adversely impact systemefficiency,equipment lifespan, and overall grid reliability. Conventional passive filters provide limited dynamic compensation andaresensitivetogrid variations. To address these limitations, active power filters (APFs) and hybrid active power filters (HAPFs) have gainedprominence,with shunt APFs recognized for effective harmonic mitigation and reactive power control. Recent research emphasizesreducingswitching device count, improving efficiency, and adopting transformer-less and multilevel inverter configurations toachievecompactand high-performance designs. This paper reviews key power quality issues in grid-connected PV and WECS systems, evaluatesbasicand advanced APF topologies, and discusses control strategies and implementation considerations. Potential researchdirectionsarehighlighted to support the development of cost-effective and reliable APF solutions for future renewable-integrated power networks.