Characteristic Analysis On Transient Signal Of Gas Insulated Substation

Compared with Air Insulated Substation (AIS), Gas Insulated Substation (GIS) has many merits, so it has been applied widely in the world. But just as the application of many new techniques, many problems have been found during the operating of GIS. On the base of some research results, the interior and exterior model of GIS are set up in this paper, and Very Fast Transient Overvoltage (VFTO)can be calculated via the software that is called EMTP-ATP. At the same time, the distribution of Partial Discharge (PD) on one bay in GIS can be also calculated via EMTP-ATP. In this paper, a new method that is called joint time-frequency analysis (JTFA) is used to analyze the VFTO and PD signals of computer simulation, the effects are very good. On one hand, the more accuracy and the larger number of characteristics of VFTO are obtained; on the other hand, It is possible that JTFA provides a more accurate and credible method to identify and locate the GIS PD signals, which shows there are huge potential applications for JTFA in electric power systems.