Current transformers and coupling-capacitor voltage transformers in real-time simulations

This paper describes two models: a saturable current transformer model ((CT) and a wide-band coupling capacitor voltage transformelr suitable for real-time transients simulation. By using very efficient network reduction and network synthesis techniques, the operations count for these models is kept to a minimum. The accuracy of the models has been tested in connection with our real-time transients simulator RTNS [l] and compared to conventional EMTP models [2]. Kevwords: Current transformers, coupling capacitor voltage transformers, EMT modelling, real-time simulation. secondary current from the known primary current is described here, a) Equivalent circuit A equivalent circuit Of the current transformer is Shown in Fig. 1 with all quantities referred to