Application of digital filters for on-site partial discharge detection on high voltage cables

There are a lot of problems for a sensitive on-site partial discharge (PD) detection on high voltage cables caused by ambient noises. The PD pulses are often superposed by various noise signals which have different characteristics in the time and frequency domain. For a sensitive on-site PD detection these disturbances have to be reduced or separated. A suitable solution of this problem can be achieved by the application of digital filters. A specially tuned digital LMS-filter which is for the first time applied for noise suppression in PD detection on high voltage cables is described. The LMS-filter works in the time domain and suppresses continuous noise signals