Digital time-domain investigation of transient behaviour of coupling capacitor voltage transformer

This paper reports a set of digital time-domain simulation studies conducted on TEHMPl61A Coupling Capacitor Voltage Transformer (CCVT) of Haefely-Trench. The Electro-Magnetic Transients Program (EMTP) is used to develop the CCVT model and conduct the transient studies. The accuracy of the CCVT model is verified through comparison of the EMTP simulation results with those obtained from test results. The investigations demonstrate that the developed model can accurately predict CCVT transient response, e.g. the phenomenon of ferroresonance. The model is developed (1) to determine impact of transients on CCVT response, (2) to design, optimize and compare protective and ferroresonance suppressor devices of CCVT, and (3) to predict CCVT transient response on power system monitoring and protection schemes.