Computation And Analysis On Dielectric Recovery Characteristic In High Voltage SF₆ Circuit Breaker

The investigation of dielectric recovery characteristic is very important to develop and design high-voltage circuit breakers. And most of investigators are working on the modeling aspects of circuit breaker arcs, the numerical simulations of electric field and flow field, nonlinear technology and many subjects, which have been the dominant sign in design of circuit breaker. In this dissertation, the detailed theoretical investigations and computerized simulations, which have close relationship to the dielectric recovery characteristic of SF₆ circuit breaker, are analyzed thoroughly. A novel approach for computing the flow field is presented, dielectric recovery characteristic of circuit breaker under various situations is analyzed, and a set of simulation software has been developed. Fairly agreement between the computing results and practical situation has been achieved.Based on the previous research, from seven aspects the research work is carried out to investigate the dielectric recovery characteristic of SF₆ high-voltage circuit breaker in this dissertation, main works are as follows:1. SF₆ is widely used in high-voltage circuit breakers because of its excellent insulating performance in uniform electric field. However, the application of SF₆ gas is restricted due to its insulating performance reduced greatly in nonuniformity cases. The uniformity of electric field becomes the bottleneck of restricting the development of circuit breaker as increasing of voltage level, enhancing interrupting capacity and miniaturization. The improved taboo search algorithm (TABU) is introduced in designing high voltage circuit breaker for the first time. Based on modern optimization method, the shield of 500kV 1-break SF₆ circuit breaker is optimized, and the actual results show that: the solution of inverse problem play an important role in design of high-voltage circuit breaker.2. The analysis on the flow field of circuit breaker is important for investigating the interrupting characteristic. The computing of the flow field within the SF₆ circuit breaker is extremely difficult due to the complex flow path with supersonic nozzle, active, viscous, compressible, variable boundary, and some intricate physical phenomena, such as the shock wave and vortices during the interrupting. In recent years, inherent weakness has been reported lies in the simplifications of computing structure and modelling. To solve the numerical problem with complex flow path and space-time processing synchronously, the improved combined method of finite volume technique and total variation diminish scheme (TVD) has been presented. And some novel methods and technologies have been proposed and applied, such as...