Study of Decaying DC Removal Techniques

Abstract

The fault current in a power system consists of three components namely: fundamental frequency component, harmonics and a DC component. The relays associated with power systems can easily discriminate between fundamental and harmonic components but when it comes to dc component or dc offset these relays are helpless. In this thesis the authors have studied various filtering techniques used for the removal of the above mentioned dc component. The various filtering techniques discussed are:
1-Lowpass Highpass Filtering technique.
2- Kalman Filtering technique.
3-FIR/IIR Filtering technique.