CONFIGURATION DESIGN AND ELECTRIC FIELD OPTIMIZATION OF HIGH VOLTAGE VACUUM INTERRUPTERS

摘要

Electric field optimization is a main task of designing high voltage vacuum interrupters. A new method of electric field design of high voltage vacuum interrupters is proposed. Firstly clearance between open contacts was given by calculation and experience. Then according to the multi-gap insulation effect and the vulnerable breakdown spots theory, utilizing the symmetrical voltage shields were proved to be helpful. With finite element method and optimization theory, a mathematical model of electrical field intensity in interrupters was given. By solved this optimization model with finite element software, a more symmetrical electric field in vacuum interrupters was obtained and its peak value appeared in the second auxiliary gaps (the two gaps between the center floating shield and the symmetrical voltage shields). So with this optimized configuration the vacuum interrupters can endure higher static breakdown voltage and higher transient recovery voltage.