Design of ferroresonance suppression circuit for capacitive voltage transformer - analytical approach supported by simulation

Design of ferroresonance suppression circuit for capacitive voltage transformer is presented. For this purpose an analytical approach to ferroresonance is firstly introduced. With use of the harmonic balance method the condition for avoiding stable subharmonic oscillations of the 3
^rd
mode is stated. In the next step the ATP-EMTP simulation based investigations are carried out to find the suppression circuit parameter (or parameters) which assure damping of the nonlinear oscillations in accordance to the requirements of the standards. Two kinds of suppression circuits designed for the considered capacitive voltage transformer construction are investigated. The obtained results are presented and discussed.