An estimation method of main-circuit insulation test for UHV GIS equipment

This paper presents an electrical parameter estimation method of the main-circuit insulation test for 1100kV gas insulated switchgear (GIS) equipment in order to realize the rationality of the test segmentation, equipment selection and parameter matching. First, the test method of main-circuit insulation is given. Then, the methods of estimating test capability of the variable-frequency series-resonant (VFSR) device with or without parallel compensation are presented considering the limitation of electrical frequency and equipment capacity. Next, a method how to estimate electrical parameters of the main-circuit insulation test of the ultra-high voltage (UHV) GIS when specifying test range is proposed. Finally, an example of UHV GIS main-circuit insulation test is given, to estimate the test capability of VFSR device and to verify the accuracy of the electrical variables estimation method. The estimation method can accurately evaluate the test capability of VFSR device and realize the accurate estimation of the electrical parameters when specifying test range, which provides a reliable reference for the test segmentation and equipment selection of the UHV GIS main-circuit insulation test.