Separation of corona noise from on-line partial discharge monitoring of power cables

The use of traditional maintenance scheme such as corrective maintenance and preventative maintenance are insufficient to prevent costly events triggered by failure of power system equipment. On-line condition monitoring is increasingly becoming popular. It is non-destructive and cost-saving as it can be carried out with the equipment kept in-service. The on-line monitoring of partial discharges (PD) in power cables in outdoor substation has lots of background noise, especially corona discharge. Thus, it is important to remove corona noise from the monitoring of PD in power cables. A new method to remove the corona noise was proposed in this paper. It involved the use of simultaneous multi-channel measurement, principal component analysis (PCA) and clustering analysis.