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Study on Electrical Characteristics of 550 kV GIL Three-post Insulator After Mechanical Load Tests

Special Session > SS3 - Advanced Sensing, Monitoring and Diagnosis in Smart Grid

GIL three-post insulator works in a complex environment of electric-thermal-force coupling field, and its mechanical and electrical characteristics are directly related to the safe and stable operation of GIL. In this paper, radial and axial load tests of 550 kV GIL three-post insulators are carried out, and the partial discharge characteristics and surface flashover charac-teristics of the insulators under power frequency voltage and lightning impulse voltage are studied after different load tests. The results show that the maximum partial discharge of 550 kV GIL three-post insulator under power frequency voltage is 1.41 pC after 30 kN, 50 kN and 60 kN radial load test. After the axial load tests of 3 kN, 4 kN and 5 kN, the maximum partial discharge capacity under power frequency voltage is 1.85 pC. Under the lightning impulse voltage test with 1675 kV peak value and 1.2/50 μs lighting wave, no flashover and breakdown occurred after radial and axial load tests.