Analysis And Optimal Design Of Transmission Characteristics Of Medium Voltage Vacuum Circuit Breaker

The spring operating mechanism has been widely used in medium voltage vacuum circuit breakers.The quality of the mechanism directly affects the electrical performance of the circuit breaker.The theoretical analysis of the mechanism and the optimal design have important practical significance.This paper takes ABB’s medium voltage vacuum circuit breaker EL spring operating mechanism as the research object,analyzes its transmission characteristics in the closing process,optimizes the transmission chain parameters,and improves the energy matching relationship in the closing phase.This paper uses Solidworks to establish a modular spring operating mechanism model for medium voltage vacuum circuit breakers.The working principle of the spring operating mechanism of the medium voltage vacuum circuit breaker is analyzed,and the composition of the spring operating mechanism and the operating principle in the three stages of energy storage,closing and opening are introduced in detail.According to the plane diagram of the mechanism,the force value of the opening and closing spring of the mechanism during the closing process is equivalent to the moving contact through torque transmission analysis,and the composition of the driving force and the resistance force during the closing process is analyzed.The load characteristic analysis and energy matching relationship of the moving contact in the closing process of the medium voltage vacuum circuit breaker are analyzed.Through the graphic method,the speed ratio and equivalent mass of the mechanism in the closing process are obtained,and the closing speed is obtained accordingly.By changing the initial force value of the closing and opening springs respectively,the changes in the closing characteristic curve and closing energy of the circuit breaker are explored.The algorithm is used to optimize the length of the four-bar mechanism in the spring operating mechanism and the initial force value of the opening spring.The comparison of particle swarm algorithm,genetic algorithm and genetic particle swarm algorithm shows that the genetic particle swarm algorithm has a better optimization effect and effectively improves the energy matching relationship in the closing phase.The virtual prototype of the spring operating mechanism was established,and the factors affecting the closing motion characteristics of the circuit breaker were explored.The transmission chain data obtained after the optimization of the genetic particle swarm algorithm was remodeled and simplified by the Solidworks software and then imported into the dynamic simulation software Adams.The new virtual prototype of the spring operating mechanism simulates the closing process of the circuit breaker and verifies the optimization results and theoretical analysis.Finally,the test prototype is assembled,and the mechanical characteristics of the test prototype are tested.By modifying the length of the four-bar mechanism and the initial force value of the opening and closing springs,and collecting various data during the closing process,the correctness of theoretical analysis,algorithm optimization and dynamic simulation is further verified.And through the Matlab platform to build the graphical optimization interface of the mechanism,it provides a quantitative analysis basis for the optimization design of the operating mechanism and the transmission scheme.This article summarizes the transmission chain analysis method that can be applied to the spring operating mechanism of the medium voltage vacuum circuit breaker in the analysis of the mechanism transmission process,which can be used to analyze the load characteristics of the mechanism moving contact during the closing process and the energy in the closing phase,and Algorithmic optimization of the length of the four-bar mechanism and the opening and closing spring force value,to improve the energy matching relationship in the closing phase,and to develop a graphical user interface for the optimization system.Adams simulation and field tests are also used to verify the theoretical calculation and optimization results.It has strong versatility and accuracy in the research and development and design of the vacuum circuit breaker spring operating mechanism.It is a perfect solution for the vacuum circuit breaker spring operating mechanism and transmission scheme.Optimized design provides a basis for quantitative analysis.