Study on ultrasonic signal characteristics of typical partial discharge types in switchgear

To identify and differentiate common partial discharge faults in 10 kV switchgear, a simulation and detection platform for switchgear partial discharge faults was established. A partial discharge identification method based on ultrasonic signal characteristics was proposed. The transient impulse quantities of ultrasonic signals during partial discharge were extracted, and their probability density distribution was used for type discrimination. A comparative study was conducted on the probability density distribution charts of transient impulse quantities of ultrasonic signals generated by four different partial discharge models. The results indicate that with the increase in voltage level, the curves shift towards higher transient impulse quantities and exhibit a 'multi-peak' pattern. Curves generated by the same type of fault overlap in height, while curves generated by different types of faults show significant differences. This approach can be used to discriminate the type of partial discharge in 10 kV switchgear.