Transient Enclosure Voltage (TEV) measurement system of UHV GIS and TEV statistical characterization

Transient Enclosure Voltage (TEV) generated during Ultra High Voltage (UHV) Gas Insulated Switchgear (GIS) switch operation is a consequence of the propagation of voltage steps created by the voltage collapse across the inter-contact gap at striking. Excessive TEV may damage primary and secondary equipment which connected with the shell of GIS, accurate measurement of TEV is necessary and important. The resistive impedance voltage divider to measure TEV mentioned by IEC 61321-1, but it does not provide a specific measurement system and measurement procedure, reports on TEV measurement of UHV GIS are particularly rare. Based on the resistive impedance voltage divider method, this paper provides TEV measurement system of UHV GIS, and the electromagnetic shielding measures are adopted to the system. To understand TEV characteristics of UHV GIS, TEV tests have been carried out in test circuit of full scale UHV GIS. Firstly, we designed and developed TEV Measurement System (TEVMS), and demonstrated its efficiency with performance tests. Secondly, operated disconnect switch (DS) of UHV GIS test circuit, we obtained the complete and accurate TEV waveforms on the different measurement locations which can generate severe TEV. Lastly, both time and frequency domain statistical characteristics of TEV waveforms were presented. TEVMS which designed and developed by us, can accurately measure TEV of GIS, applies not only to the UHV GIS, but also applies to other voltage levels of GIS. TEVMS and experimental data are suitable to used by engineers and designers in TEV calculation, TEV measurement, insulation cooperation, and equipment arrangement optimization.