Computer — Aided partial discharge measurements

An instrument is described which makes computer assisted measurements for the identification of the source and nature of partial discharges which may occur in an insulation system. The instrument accepts pulse count, phase, and voltage magnitude information from a commercially available partial discharge detector of the resonant-coupled type. These signals are then processed for further analysis. This partial discharge analysis information, when received by the personal computer, may be displayed in graphical form of discharges vs. phase, or by histograms of count of pulse heights. The instrument software also includes a partial discharge identification algorithm programmed using the language of an expert system shell. This algorithm, which uses data acquired from the partial discharge test, and further data derived from intermediate calculations together with queries to the operator, will provide additional information about the site and nature of the partial discharges. The expert system has the capability of identifying many types of discharge phenomena. The results obtained with the system may be displayed on a screen or a plotter, to provide hard copy.