CURRENT DISTRIBUTION AND POWER LOSS WITHIN THE SLIDING CONTACT STRUCTURE OF VACUUM CIRCUIT BREAKER

摘要

Power loss and Temperature rise are key characteristics which must be considered carefully when designing a high voltage circuit breaker. In this paper, a model for a whole sliding contact structure used in a high voltage vacuum circuit breaker has been created. It is composed by an inner cylinder conductor, an outer tube conductor and 2~4 rows of sliding contacts between the former two conductors. Current distribution, resistance and power loss features of the whole structure have been analyzed by Finite Element Method (FEM) software. The influences of different geometric and electric parameters have been considered thoughtfully based on current skin effect, including the radius of inner cylinder conductor, the thickness of outer tube conductor, the overtop length of outer tube conductor, the spacing between contacts, the equal resistivity of sliding contact, and the number of contacts rows. Furthermore, some suggestions on selecting parameters to reduce the resistance and power loss of the whole structure have been pointed out. For copper and structure assigned, 11 mm is the optimal thickness of outer tube conductor, more than 35 mm should be chosen as the radius of inner cylinder conductor, and it will be better to reduce other dimensions.