Internal Fault Diagnosis and Defect Position Analysis of a 1000kV Shunt Reactor with Abnormal Oil Chromatography

There is a fault case caused by abnormal C2H2 content in a 1000kV shunt reactor of ultra high voltage (UHV) substation. In this paper, a preliminary analysis of the fault type is firstly conducted based on online oil chromatography data. Secondly, it can be judged that there is a significant discharge inside the shunt reactor considering typical ultra high frequency (UHF) and high frequency (HF) discharge signals measured by partial discharge intensive care system. Finally, fault diagnosis and defect position are conducted by combined detection of UHF partial discharge, HF partial discharge and ultrasonic partial discharge. It is found that the defect position of UHF partial discharge and ultrasonic partial discharge are easily affected by complex structure inside the shunt reactor, which can only locate approximate area. Meanwhile, by comparing the size and polarity of the HF partial discharge pulse waveform of the shunt reactor iron core and the clamp with the test results of the square wave discharge polarity meter, it can be judged that the X-pillar clamp has a discharge source to the ground loop. The effectiveness of the combined diagnosis and positioning method of HF partial discharge, ultrasonic partial discharge, and UHF partial discharge are verified as to the disintegration results of returning to the factory. It can provide a reference for fault diagnosis and position analysis of UHV shunt reactors.