VERIFICATION OF THE SEISMIC RESISTANCE OF GAS-INSULATED SWITCHGEAR (GIS)

After a brief introduction into the background of seismic requirements the- paper describes the test procedures, demonstrating the capability of gas insulated switchgear to withstand seismic stresses up to highest ground accelerations of 0.75 g. The verification methods for checking the test object after test are described also. As vibrational tests are very cost intensive and therefore can only be performed with a representative switchgear arrangement, calculation methods for demonstrating the seismic withstand behaviour of practical switchgear arrangements are needed. A calculation model will be described, adopted to the results of the representative seismic tests. The tests and calculation results demonstrate the suitability of a 3pole common enclosed GIS design for 145/170 kV for horizontal ground accelerations up to 0.75 g.