DESIGN AND DEVELOPMENT OF TUNED PASSIVE FILTERS FOR HARMONIC ELIMINATION

Abstract

In present days, the wide spread use of non-linear loads and electronics switched loads has led to increased harmonics in both current and voltage waveforms. These harmonics may cause malfunction of equipment, additional heating losses, excessive voltage stresses and overloading. To overcome such problems, harmonic mitigation is becoming very important for both utilities and customers. If the order of harmonics is very high we can easily filter them out using standard low pass filter configurations. But lower order harmonics poses problems in elimination. Different passive filter configurations were proposed for selective frequency component elimination. These are classified as single tuned, double tuned and three tuned filters. These filters bypass the selected frequency component to ground by offering negligible impedance at that frequency. In these circuits resistor is not advisable to use as it consumes active power. This report presents the design principles, major technical features and algorithms to calculate the parameters of above mentioned filters. They are simulated using MATLAB/SIMULINK. Comparative analysis presented among the filters designed. Hardware implementation of three .tuned filter to tune 3' , 5th and 7th harmonics in input current to non-linear load is carried out and Performance characteristics are compared with simulation results.