Study On DC Partial Discharge Detection System Of High Voltage Storage Capacitor

The insulation capability of High Voltage Storage Capacitor (HVSC), which is the kernel of impulse power, determines the service reliability of impulse power system. In nowadays, only capacitance, dielectric loss or discharge times are counted as characteristics of capacitors. These parameters, a) can't find out the failure inside when it comes out of manufacturer;b) can't evaluate the capacitors when they're in service. However, Partial Discharge (PD), which is widely used as a parameter of inside failure in insulation, is considered that it should be useful in capacitor. But, almost all the PD tests are based on power frequency and low capacitance sample, whose sensitivity, analysis methods etc. are not suitable for HVSC.This thesis works on the DC PD detection system which is designed for HVSC specially. First, the thesis starts off PD mechanism, and analyses the noise and its source. Then, a high sensitivity and noise rejection DC PD detection system is designed. And, in order to make every test comparable, a PD calibration system was decided. This system is validated though a series of test. At last, wavelet transfer is selected as powerful digital filter after compared with others.All the work the thesis introduced can be used in HVSC factory detection and in service performance check, and it's useful for manufacturer to improve their craft or check their equipments. At the same time, it's also the basic of further PD research on the patterns how discharge developed.