MITIGATION OF TRANSIENT OVER-VOLTAGES AND VFTO EFFECTS ON GAS INSULATED SUBSTATION

Abstract

Gas Insulated Substations (GISs) have found a broad range of applications in power system over the last three decades because of their high reliability, easy maintenance, small ground space requirements, etc. Although GIS have been involved in power systems since long time ago, some of the problems are of more attention. These problems include generation and propagation of very fast transient over-voltages (VFTO) during switching of circuit breakers or disconnector switches or earth faults. In this research the investigation is on VFTO by putting intelligible models for a GIS of a capacity 400 KV. This paper presents a modeling guideline for VFTO analysis in GIS and, further mitigation techniques such as Nano-crystalline Rings, RC Filter, RF Resonator etc. have been studied by MATLAB Software.VFTO effect on GIS such as stress on substation Transformer leading to winding deformation has been discussed in this paper andlocalization of deformation and type of deformation in transformer winding is also carried out using intelligent classifier.