Preliminary study on the structure design of 330 KV GIS with three phase in one tank

This paper focus on the research about the probability and practicability of 330 kV GIS structure design with three phase in one tank， which represents the miniaturisation and compact developing trend of GIS. The design principle is proposed according to the volume of three phase in one tank (structure A) is generally smaller than that of the sum volume of three single phase (structure B). Then, the dimension size of 330 kV GIS with structure A is presented. To solve the weak insulation-level problem between phases of structure A, which prevents it from being used in high-voltage power system especially above 330 kV, an electromagnetic-temperature-flow multi-physical field coupling model considering eddy effect and skin effect is established to analyse the influencing factors on the insulation level of internal GIS. Therefore， the insulation level between the phases of structure A is calculated under the condition of power frequency and short circuit, respectively. The results show that the insulation margin of 330 kV GIS with structure A is enough and completely meet the insulation requirement of GIS. Furthermore, compared with structure B, structure A has lower temperature rise and energy consumption.