Measurement and computation of the excitation curve and loss angle of instrument voltage transformers

This paper introduces a method to obtain the excitation characteristics of instrument voltage transformers without parasitic influences from secondary side measurements. The effective winding capacitance of instrument voltage transformers (IVT) is modeled and measured. The capacitive current is subsequently subtracted from the data obtained by a measurement. The excitation current and loss angle can be obtained from measurements at rated frequency and of the frequency dependence of the impedance from the secondary side of the transformer.