This document discusses improving power quality using active filters. It provides an overview of various power quality issues caused by harmonic pollution and reactive power in distribution systems. Active filters are presented as an effective solution to power quality problems. The document describes different types of active filters, including shunt and series active filters, and their applications in compensating for issues like harmonics, reactive power, voltage fluctuations, and unbalanced currents. Control strategies for active filters are also discussed. The document aims to give researchers and engineers an understanding of active filter technology and its role in addressing common power quality problems.