Partial discharge test as a non-destructive diagnostic tool for electrical apparatus

Partial Discharge test is a non-destructive over-potential test which demonstrates the condition of the insulation prior to breakdown. Such a test is assuming greater significance particularly in high voltage apparatus where an economical design of insulation is desirable. Partial discharge tests are being introduced as routine tests for high voltage apparatus. Various methods are in use for partial discharge tests. Of these methods, measurement by discharge detector gives quantitative information. In this paper results of discharge measurements on two typical high voltage coils, one completed motor and a transformer are given. Results of discharge tests on a few typical insulating materials are also given.