Sensitive insulator-a new method to detect the faulty porcelain suspension insulator

The porcelain suspension insulators are destroyed by mechanical power, alternation of cool-heat while running on the transmission line, which leads to power faults. Finding the faulty insulator out before the fault occurs becomes more and more important. At present the most useful method is to measure the distributed voltage which is not refined. Therefore a new method is developed. When there is a faulty insulator, the distributed voltage of other fine insulators will change. Moreover the changing degree is different according to the damaged degree and the location of the faulty insulator. But there is always a sensitive insulator when the faulty insulator is rather dangerous. Measuring the voltage of that insulator can make the status of the others clear. In the laboratory, the situations of 110 kV and 220 kV have been simulated and the conclusions have been obtained. The distribution voltage of the 4^th insulator from the earth is the sensitive insulator. The threshold is 6%, if the measured voltage of 4^th insulator is 6% higher than the standard voltage, there must be a faulty insulator in the string