A Utility Method of a High Voltage Vacuum Interrupter Design

Electric fields optimization is a main task of designing high voltage vacuum interrupters. A new method of electric fields 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 methods and optimization theory, a mathematical model of electrical fields intensity in interrupters was given. By solved this optimized model with finite element software, a more symmetrical electric fields 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