Development of real-time system for simultaneous observation of visual discharges and leakage current on contaminated DC insulators

A novel real-time observation system has been developed. It is capable of simultaneously recording visual partial discharge arcs and leakage currents on insulator surfaces under wet-contaminated conditions during a 2-h test. Since this system uses a video recording system uses a video recording system, the discharges and currents can be reproduced repeatedly even at a slowed-down speed. To permit simultaneous recording and accurate data processing of leakage currents, a personal computer is also employed. It was found that the sampling frequency of 1.0 kHz was satisfactory for the recording of the leakage current. Another function of the computer is to exhibit the contours of insulators to be tested in a dark room so that the locations where the arcs stay can be clearly identified. Tests by the clean fog procedure confirmed the good performance of the system at the time of the design. Some experimental results and the applicability of this system are discussed