Harmonic Resposnse Tests on Voltage Transducers for the New Zealand Power System

This paper presents the results of harmonic response tests carried out on capacitive voltage transformers, as used on the New Zealand 220 kV a.c. network. It is shown that the harmonic response measured using low voltage test equipment is considerably different from that obtained at high voltage. The latter is highly non-linear and is affected by the specific magnetization characteristic of the CVT tested. It is concluded that for field measurement of harmonics at rated voltage, the transformer of a CVT unit should be disconnected and the CVT used as a purely capacitive or resistor-capacitor divider.