In industrial and utility power system it has been observed that harmonics build a major role in reducing the quality of power. These harmonics are caused because of increasingly utilize of nonlinear loads connected to the power system. In this context, active power filters play a very significant role for improvement in power quality. Moreover, at transmission ground, there is a high requirement to control reactive power and voltage stability. Conventionally, passive and active filters (shunt and series filters) were used for the development of power quality. But, they suffered from the issues like resonance, fixed compensation, and other heating networks are commonly addressed in the literature as one of the most effective solutions for decreasing the designed.

Power system comprises of threenatural / physical characteristics namely voltage,current and frequency. Deviation in these physicalcharacteristics are termed as power quality issues inpower system. Presence of nonlinear current ornonlinear/unbalanced voltages and frequencies aretermed as power quality issue. These (current, voltageand frequencies) deviations result in failure/damageof equipment in power system. Power electronicconverters associated with their nonlinear switchingcharacteristics and high frequency operation are themajor cause for power quality issues. In order toreduce harmonics and improve power quality, HybridActive Power Filter (HAPF) or shunt HAPF can beemployed. The power improvement can be done usingvarious algorithm like RLS algorithm, DC link voltagecontroller, fuzzy logic based hybrid filter.