S.V.Purnima, C.Gomathi, S.Sathya, T.Snekapriya
Interference due to harmonics, and generated by power electronic devices, has become a serious problem, because converters are nowadays more and more frequently used in transmission and distribution systems and in power plants. The most natural, suitable way to solve these problems is the introduction of filtering actions. Passive LC filters have long been used to absorb harmonic current of non-linear loads. Due to some disadvantages of passive filters the concept of active filters were proposed. There are so many different controlling algorithms and topologies available for active filter. Here Pulse Width Modulation based topology is used. This paper analyzes the comparative merits of Sinusoidal Pulse Width Modulation (SPWM) and Variable Index Pulse Width Modulation (VIPWM) techniques and the suitability of these techniques in a Shunt Active Filter. The objective is to select the scheme which provides improved output current harmonics. Simulation Results are presented in MATLAB/SIMULINK. Results show that the proposed method is effective cancel out the undesirable harmonics