Research On Several Key Technologies Of High-Speed Vacuum Circuit Breaker And Its Applications

Circuit breaker is the most important protection and control equipment in power system.With the continuous development of power industry,power system puts forward higher requirements for the speed of circuit breaker.High speed vacuum circuit breaker based on electromagnetic repulsion mechanism(ERM)has broad application prospects in fault current limiting,DC interruption,voltage sag suppression and other fields.Based on the analysis of the load characteristics of vacuum switch and the output force characteristics of operating mechanism,a permanent magnet electromagnetic repulsion mechanism(PMERM)based on permanent magnet mechanism closing and electromagnetic repulsion mechanism opening is designed,and the model of high speed vacuum circuit breaker based on PMERM is established.The dynamic analysis of the closing and opening process is carried out,and the kinematics equation of the closing and opening process is deduced.The simulation model of ERM is established by using finite element analysis software Ansys Maxwell.The multi-objective optimization theory is introduced to optimize the design of ERM.Taking the maximum displacement in 3ms and efficiency of the ERM as the optimization objective,the unified objective function is constructed by using the linear weighted combination method.The single variable method is used to optimize the ERM.The influence of the parameters on the quality of the moving part of the mechanism is considered while the structural parameters are changed.The effects of parameters of ERM,external circuit parameters and load characteristics on its dynamic characteristics are studied by simulation.The differences of dynamic characteristics between Coil-Disc ERM and Double-Coil ERM are compared.Based on the kinematics and dynamics analysis,the influence of transmission ratio on its dynamic characteristics is studied,and the formula for calculating the optimal transmission ratio is deduced.The simulation model of non-direct high speed vacuum circuit breaker is established by using field-circuit coupling simulation software Ansys Simplorer in multi-physical domain.The influence of transmission ratio on the dynamic characteristics of opening is simulated and analyzed.A test platform for non-direct high speed vacuum circuit breaker is built.The correctness of theoretical derivation and simulation analysis is verified by experiments.Aiming at the problem of opening buffer of high speed vacuum circuit breaker based on PMERM,a opening buffer method of short closing coil during opening process is proposed.A simulation model of opening buffer is established by using field-circuit coupling simulation software Ansys Simplorer,and the characteristics of switching buffer are simulated and analyzed.Finally,the validity of the buffer method is verified by the prototype test.A pulse closing vacuum switch(PCVS)based on PMERM is designed.A multi-physical field-circuit coupling simulation model of the PCVS is established in Ansys Simplorer to simulate and analyze the dynamic process of the pulse closing.A 27.5 kV prototype of the PCVS is manufactured and the mechanical and electrical performances are tested.The simulations and experiments both approve that the contact time between the moveable contact and static contact can be controlled to be less than 6ms.This meets the pulse-closing technology requirement.A fault location system for catenary based on pulse closing technology and traveling wave technology is constructed by using the prototype of PCVS,and field tests are carried out.