A Method of Monitoring Partial Discharge in Switchgear Based on Ozone Concentration

We accurately established an air discharge simulation experiment system to obtain the variation of ozone concentration in air discharge process, which includes pin-to-plate discharge, air-gap discharge, creeping discharge as well as metal particle discharge model, consisting of voltage console, transformer, and discharge device, gas absorption cell, spectrometer, and computer. Through online monitoring, the ozone concentration in a relatively closed container to simulate internal partial discharges for an hour with the voltage increases from 3 to 0.2 kV increment, we obtained four basic models with discharge inception voltage grade of 4.0, 4.5, 4.7, and 4.1. Besides, we applied the method of Fourier transform-differential absorption spectroscopy to process and analyze the experimental data, and obtained the ozone concentration curve. The ozone concentration increases with the increasing voltage loading time, and it tends to be stable and reaches an equilibrium state under a certain voltage.