Theoretical Analysis And Optimization Design Of The Opening And Closing Of Medium Voltage Vacuum Circuit Breaker

The vacuum circuit breaker is one of the main electrical appliances in the medium voltage switch.The spring operating mechanism is widely used in vacuum circuit breakers due to its low power requirements and high operational reliability.Although the research on the spring operating mechanism of vacuum circuit breakers is relatively mature,there are still many shortcomings in the study of its mechanical properties.This article takes the spring operating mechanism of the medium-voltage vacuum circuit breaker as the research object,and theoretically analyzes the driving force,resistance change and energy change of the moving contact of the spring operating mechanism during the closing process.Firstly,The article uses the 3D modeling software SolidWorks to establish the mechanism model,By analyzing the position and torque change of the mechanism during the closing process,we can obtain the change curve of the driving force and resistance to the moving contact during the closing process.The article uses MATLAB to solve the intersection of the driving force and the resistance change curve of the moving contact during the closing process,calculate and compare the driving force of the driving force and the resistance before the intersection,and analyze the driving force of the normal closing of the circuit breaker.The energy relationship between resistance and work,Finally draws an analytical calculation method that can be used to analyze the driving force and resistance change and energy change of the moving contact in the closing process.Secondly,this paper uses SolidWorks to establish a simplified model of the medium-voltage vacuum circuit breaker spring operating mechanism,and introduces the multi-body dynamics simulation software Adams to establish a virtual prototype.Adjust the parameters of the energy storage spring,the opening spring and the overtravel spring separately,change the driving force and the resistance work force of the moving contact in the closing process,Find out the mechanism parameters when the circuit breaker can just close,and substitute it into the analytical calculation method to analyze the energy relationship at this time.Comparing the three sets of simulation and theoretical analysis results,the energy relationship between the driving force and the resistance work is obtained when the circuit breaker can be closed,and the correctness of the analytical calculation method is verified.Finally,on this basis,we can find the influence of the friction force of the mechanism on the energy of the closing processFinally,we select a circuit breaker for mechanical characteristics test.By adjusting the mechanism parameters,the circuit breaker can just complete the closing,calculate and compare the relationship between the driving force and the resistance work done by the moving contact at this time,and further verify the correctness of the analytical calculation method.This paper analyzes the spring operating mechanism of medium voltage vacuum circuit breaker from the perspectives of theory,simulation and experiment,and proposes an analytical calculation method for the driving force and resistance change and energy change of the moving contact in the closing process.The simulation analysis shows the energy relationship between the driving force and the resistance work of the moving contact when the circuit breaker can be closed,and verifies the correctness of the analytical calculation method.Finally,the simulation results and the correctness of the analytical calculation method are further verified by the prototype test.The analytical calculation method can provide a theoretical basis for the development and design of the circuit breaker,reduce the design cycle and improve the design efficiency.