The exorbitant use of power converters and non-linear load on power system have led to polluted power supply. In the past era the cable used for 3-phase supply used to be 3.5 cable i.e one each for R phase, Y phase and B phase and half this cross section for neutral. Now a days the cross-sectional area required for neutral is almost twice the cross-sectional area of the one used for each phase. The pollution of the supply means the distortion of current and voltage waveforms which should have been purely sinusoidal otherwise. A large amount of harmonics are fed into the supply through power converters which include 1-phase & 3-phase rectifiers, thyristor converters and other power electronics components. The design and operation of all the power system & its components is simpler if it is a sinusoidal voltage at constant frequency. The injection of harmonics also results in reduced efficiency and less power factor. This can be minimized using shunt filter which can be either tuned L-C Filter or High pass filter. Another option in this regard is active filter. Active filter when connected in series with the load are called as series filters and when in parallel, called as shunt filters. This paper mainly deals with how a shunt filter enhances the power quality by cancelling the harmonics. Voltage source Inverters (VSI) are normally employed in active filters for storing energy. Pulse Width Modulation (PWM) techniques along with the VSI is the latest trend in the new era control topologies.