Probabilistic framework for vulnerability analysis of coupling capacitor voltage transformer to ferroresonance phenomenon.

The performance of measurement transformers especially in transient phenomena affects the monitoring, control and protective devices. Coupling capacitor voltage transformer (CCVT) is a measurement transformer that may experience ferroresonance phenomenon due to the presence of capacitors and non‐linear reactors. This study provides a probabilistic framework for investigation of ferroresonance phenomenon in CCVT. The aim of this investigation is to find out the area of the power system in which a CCVT is highly prone to experience ferroresonance phenomenon. Also through this framework the behaviour of the different types of ferroresonance suppression circuits and possible solutions to avoid or reduce the chance of ferroresonance will be discussed. The effects of several factors such as switching moment, different fault type and the fault inception angle are investigated. The investigation will be conducted considering the effects of single‐pole auto‐reclosing, three‐pole auto‐reclosing and capacitor failure in the CCVT. As shown in the simulation results, the presented framework can provide some useful information regarding the exposure level and severity of CCVT ferroresonance in the system. [ABSTRACT FROM AUTHOR]