Quantitative evaluation method of the pressure test results of rubber and plastic insulated cable

摘要

PROBLEM TO BE SOLVED: To evaluate test results quantitatively on pressure-proof tests in consideration of a switching surge voltage and to obtain appropriate test conditions quantitatively at the time of determining the lives of cables. ;SOLUTION: The relationship between the probability that a line is destroyed during operation by an operating voltage of a predetermined switching surge voltage and the length of a water tree is obtained to obtain the probability that a water tree is destroyed in a predetermined number of years on every length of water trees. Then in a graph with the length of a water tree in the axis of abscissa and the probability of destruction in the axis of ordinate, the areas of occurrence of four types of phenomena that (1) destruction occurs by the test waveform of a predetermined voltage to be used for a life determination test and destruction occurs during operation within the predetermined number of years, (2) destruction does not occur by the test waveform and destruction occurs during operation within the predetermined number of years, (3) destruction occurs by the test waveform and destruction does not occur during operation within the predetermined number of years, and (4) destruction does not occur by the test waveform and destruction does not occur during operation within the predetermined number of years are obtained to evaluate the results of pressure-proof tests on cables from area ratios and the results by the test waveform.;COPYRIGHT: (C)2000,JPO