Performance evaluation of multi-state Kalman filter effectiveness in power system digital protection schemes

Effects of unwanted distortions on power system network voltage and current phasor quantities during faults could adversely affect the reliability and discrimination of protective relays. This paper is principally concerned with the digital relaying concept based on multi-state Kalman filtering approach to minimise such problems. It seeks to characterise the effects of noise, harmonics and DC offset distortions on Kalman estimators.