Mitigation of Ferroresonance in Capacitive Voltage Transformer Using Memelements

Abstract

Ferroresonance in power system is still an unpredictable phenomenon. Capacitor Voltage Transformer (CVT) provides signals for measurement and protective devices. Protective relays are affected by the transient response of CVT due to ferroresonance. Various ferroresonance suppression circuits (FSC) such as active, passive and electronic type filters have been proposed for CVT. This work presents a memristor and meminductor for mitigation of the ferroresonance phenomenon in CVT. A model of CVT rated at 3.3 kV/110 V is designed and the ferroresonance is created as per standard IEC 61869–5. A low pressure gas discharge lamp is used to design as a memristor emulator. By using a mutuator circuit, the meminductor emulator is derived from the developed memristor emulator. The ideal characteristics of the memristor and meminductor are verified with the designed emulators. During the inception of ferroresonance, the modelled memristor and meminductor are connected individually across the secondary to mitigate the ferroresonance. The performance of the mitigating circuits are compared with that of the conventional technique and the results of the harmonic analysis are used to select a suitable FSC for a CVT.