Corona Location inTransformersby Radio Frequency SpectrumAnalysis,PartI:Theory

After discussing transformer types, avalues, andlocation ofvoltage generators incapacitive ladder networks andequivalent transmission lines, a newelectrical technique forlocating trans- former partial discharges orcorona isdescribed. Itisbasedonthe measurement oftheradiofrequency spectra atthetransformer terminals. Provided thetransforner winding canbeapproximated toauniform transmission line forthefrequency rangeconsidered, themethodisshowntobetheoretically sound. Measurements on modelnetworks andactual transformers suggest that, atleast over certain frequency ranges, thewinding canberegarded asauniform transmission line. Apart fromlocating corona, themethodprovides a quickandaccurate meansofmeasuring actual transformer a values.