420 kV SF 6 -insulated tubular bus for the Wehr pumped-storage plant electric tests

Two 420 kV SF 6 -insulated tubular bus systems, 600m and 700m long, have been completed in the spring of 1975. The three-phase systems consist of isolated-phase transmission lines and form the power link for the Wehr pumped-storage plant. After a brief description of the electrical data specified and of the mechanical design, the authors describe the large number of electrical tests carried out. These included laboratory tests, which were concluded by type-testing of the tubular bus and metalclad surge diverter, and routine tests on insulators and diverters. Special attention was also paid to the performance of the equipment under various fictitious fault conditions, and several test series were carried out for this purpose. For the test at the site, an oscillating switching impulse voltage was applied.