USA-USSR Investigation of 1200-kV Tower Insulation

Results of the joint USA/USSR investigations on 1200-kV tower air Faps and insulator strings are reported for a comprenensive range of times to crest of applied switching impulses extending from about 100 microseconds to 6 milliseconds. Tests were performed in the USA with a conventional impulse generator and in the USSR with cascade transformers. As a result of these investigations, data are available for the first time on similar test objects stressed by two different types of voltage waveforms. A technique for comparing the results based on the concept of the "active part" of the waveshape is described and applied to the data.