Correlation Between Partial Discharge of Typical Defects in GIS and UHF Signal

In order to study the relationship between UHF signal and discharge, this paper discusses and compares the relationship between UHF signal energy and discharge through theoretical analysis and experimental research on four typical GIS defect discharge models. Firstly, the power density in the far-field and near-field is derived based on the Hertz electric dipole. Combined with the relationship between the pulse current method and the apparent discharge, it is deduced that there is a quadratic function between the UHF signal energy and the apparent discharge. Then the partial discharge model is tested by pulse current method and UHF method at the same time. 11 shows that among the four typical defects of GIS, except free metal particle discharge, the coefficient of determination between UHF signal energy and the square of partial discharge is greater than 0.9. There is a good linear relationship Between UHF signal energy and the square of partial discharge. The results are helpful to use UHF signal energy to complete the quantitative study of partial discharge and better reflect the strength of partial discharge.