Application of a triband partial discharge detector to on-site measurement

A triband-type detector having three independent amplified frequencies in a limited bandwidth as well as maximum output was developed. This method has the merit of a narrow band that is almost free from the effects of exterior noise. This method has proved to have excellent sensitivity to the reaction of partial discharge generation along generator windings. For rewinding stator coils, comparison measuring tests employing both the new and conventional discharge detectors were simultaneously carried out. The results attested to the excellent characteristics of the new detector, and variation response at each generating position of partial discharge in the windings was measured with a fair degree of accuracy