A study of short-term partial discharge aging of polypropylene film

Polypropylene film has been subjected to surface discharge of known initial maximum magnitude for different periods of time (2 to 12 h) at subatmospheric pressures ranging from 10 to 66.50 kPa, using uniform field electrodes with AC voltage stress of 625 kV/cm. By measuring the residual breakdown voltage of the aged samples, a degradation rate curve is obtained and an estimate of the life of the films under experimental conditions is attempted. These estimates are compared with results from life tests in which the samples are stressed to failure. The estimates are extended to normal service conditions. The erosion of the films is studied from microphotographs of the aged samples.<
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