80 kA短路故障下特高压GIS内部燃弧效应评估与结构失效风险分析OA

As the grid load and the degree of interconnection between substations increase,the short circuit current level rises accordingly,driving the development of 1 100 kV/63 kA GIS toward 1 100 kV/80 kA based on existing equipment,which places higher demand on the arc ablation resistance performance of the enclosure.Currently,this performance is mainly evaluated through internal fault arc tests.However,due to the difficulty of conducting tests on UHV GIS,most assessments are performed by using numercial calculations.Nevertheless,numerical methods struggle to capture the combined effects of thermal-mechanical coupling.Furthermore,due to the limitations of nu-mercial assessment methods,the evolution of arcing effects and the risk of structural failure in UHV GIS equipment under extreme fault conditions remain unclear.To address the issue,in this paper the GIS arcing effect assessment method considering thermal-mechanical effect is proposed on the basis of Mayr-Schwarz arc model and the assess-ment reliability is verified.Compared with the test result,the assessment error rate is less than 1%,indicating that the proposed assessment method and the selection of empirical parameters possess high reliability.Furthermore,based on the proposed method,the internal arcing effects of 1 100 kV/63 kA GIS busbar compartment at 80 kA short circuit fault is analyzed.The assessment result shows that in case of 80 kA short circuit current for 0.3 s,the maxi-mum pressure in the gas compartment can be up to 2.71 MPa,exceeding the enclosure maximum allowable pressure of 1.95 MPa of the busbar compartment enclosure,and the enclosure will be cracked from the weld seam.Such mea-sures as optimization of thickness and internal diameter of enclosure as well as addition of pressure relief device are suggested.The relevant work can provide a necessary theoretical basis of arcing resistance performance of three-phase independent encapsulated GIS at different voltage levels.