Proposed Methods to Reduce Transient Sheath Voltage Rise in Gas Insulated Substations

Gas insulated substation systems (GIS) are vulnerable to surges which inevitably cause transient sheath voltage rise (TSVR). This paper discusses a mathematical model to simulate short gas-insulated transmission line subjected to internal breakdown during disconnect switch operations and subsequent, restriking of the gap. A formula for the transmitted coefficient of a containment wave guide (CWG) has been developed. A study to investigate the effects of system materials and CWG on TSVR is here presented. It is shown that a combination of CWG and high permeability and resistivLty system material has a, considerable effect in decreasing and damping TSVR. This has important safety and measurement implications.