Abstract :
Following a brief résumé of available information on the wave-shapes of surges on transmission lines, the wave-shapes of impulse voltages generated in the laboratory are denned and recommendations are made for the standardization of wave-shapes in order to facilitate the comparison of results obtained in different laboratories. Standardization of impulse-testing technique is also advocated. Sparkover and puncture tests are considered in detail, and the extent of agreement of results obtained in different laboratories is indicated. Standard impulse-voltage routine and type tests are recommended for line insulators, bushings, switchgear, and transformers, and reasons are advanced for the choice of such tests. The repercussion of the introduction into national specifications of impulse-voltage testing on the existing standardized power-frequency tests is considered in detail, and recommendations are made for the elimination of some of those tests. In order to establish co-ordination between line and station apparatus under impulse voltages, a table is given showing the suggested impulse test voltages for station apparatus connected to normally-insulated transmission lines, the proposed test values being based on the British Standard Specification for line insulators now widely in use.
