PD detection has become one of the important contents of on-line testing technology in cable insulation. Due to weak PD signal and vulnerable to spot noises, how to correctly recognize and extract signal of PD become the research focus and difficulty of on-line monitoring system .This paper aims to provide a basis for judgment and effective analysis of PD on-line monitoring by using multiple anti-jamming technology to process PD signal, effectively eliminate the interference and retain necessary features of the original signal; Using multiphase spectrum clustering analysis to extract discharge characteristics from multiphase spectrum. It proves that the technology has good practicability and popularization according to the field application of 330kV cable PD on-line monitoring system of a certain Hydropower Plant .
