Algorithm for Defects Identification by the Analysis of PD Pulses in SF6 Gas

Summary

This paper described an intelligent algorithm that identifies defect type by analysis of partial discharge (PD) pulses in SF6 gas. A needle-plane electrode, plane-needle electrode, free particle and crack inside spacer were fabricated to simulate the defects in gas insulated switchgear (GIS). Each electrode system was placed at the inside of shielding enclosure and a non-inductive resistor was installed between the electrode system and ground wire. PD pulses were measured by an oscilloscope with the frequency bandwidth of 1GHz and sampling rate of 5GS/s. And data acquisition and signal processing were controlled by a LabVIEW program. Also, the digital filter was designed to eliminate a power frequency and an external noise. The parameters of a single PD pulse in relation with the polarity of power frequency were analyzed depending on defects. The physical shapes were compared by using kurtosis, skewness, and time-based parameters such as rising time, falling time, pulse-width, and maximum voltage. By applying the proposed algorithm, the identification rates were 97% in the needle-plane electrode, 96% in the plane-needle electrode, 91% in the free particle, and 93% in the crack inside spacer. From the result, it was verified that the proposed algorithm could identify the types of defects in SF6 gas.

Additional informations

Authors

Sklenicka Vaclav, Nicolopoulou Eleni, Stathopulos Ioannis, Niedik Christoph Felix, Tee ShengJi