Research of UHF calibration technique for four kinds of partial discharge defects in GIS

In order to analyze the corresponding relations between UHF signals from different kinds of defects in GIS and apparent discharge (pC), that is the calibration technique for UHF signals, four common defects in GIS are proposed in this paper, and four frequency bands including the 300~400 MHz, 700~800 MHz, 1.4~1.5 GHz and 0.3~3 GHz, are selected to calibrate the UHF signal of each defect. After that different mathematical regression models and the calibration indexes of goodness of fit are established for the regression and calibration analysis of the results. After the research, we find that there is obvious corresponding relation between the amplitude (mV) and apparent discharge for the same type of defects in different kinds of detection frequency bands. Besides, there are differences between different bands, and the unary linear polynomial regression model may be approximately used for calibrating the UHF signal amplitude for different kinds of defects.