Noise reduction and PD measurements using digital filter and signal processing technique in HV substations

It is our aim to establish a proper noise reduction algorithm for partial discharge (PD) detection and measurements of electric power apparatus by using digital signal processing techniques. Examinations of noise diminution by an adaptive predictor filter technique have been done in both the laboratory and on-site practical environments on the basis of measurements of PD signals in SF/sub 6/ gas and the real noises as well as interferences. We measured the electromagnetic noises in practical HV and EHV substations and utilized the noise reduction method. As a result, sinusoidal continuous noises were considerably reduced without a priori knowledge of PD signals and noise characteristics, so that the technique is promising to be used for future applications in actual power substations.