The setting up of conductive coupling model in gas insulated substation

In order to simulate the disturbing voltage in secondary circuits caused by disconnector or circuit breaker operations in a gas insulated substation (GIS) through conductive coupling, the conception of an entire conductive coupling model of the GIS is proposed and the model is set up. In this entire model, the high frequency inductive potential and current transformers (PT/CT) model used to simulate capacitive coupling and the multi-terminals network model for grounding systems used to simulate resistive coupling are set up using rational functions by means of vector fitting (VECTFIT) based on test data. By incorporation of them into EMTP (Electro-Magnetic-Transients Program), one can use this entire conductive coupling model of GIS to calculate not only the very fast transient overvoltages (VFTO) and transient ground potential rise (TGPR) in the primary circuits, but also the disturbing voltage in the secondary circuits in GIS.