PLL Based Hybrid Active Filter for Harmonic Suppression Caused by Non-Linear Loads

As the application of non linear loads are increasing the harmonic distortion is getting more and more serious problem because it causes the poor power factor, heating of the equipments, vibrations in machines reduction in efficiency and is more dangerous for electronic controlling devices such as microcontroller and processor as well as sensing preamplifier which can cause false sensing and unsterilized the complete control system hence the harmonic filtration is getting more attention of designer and many techniques have been already proposed to overcome the problem, in our thesis we are discussing the hybrid filters for suppression of harmonics, the hybrid filters are basically the combination of passive and active filters a combination leads to a better performance, the main concern of the thesis in on active part and we proposed a PLL based technique to control the switching of the active filter so that the harmonic distortion can be minimize furthermore the advantage of the is that it is independent of the topology of the filter weather it is serial or parallel combination which is proved by the simulation results which are obtained by the SIMULINK model.