Theoretical Calculation And Simulation Analysis Of Closing And Opening Process Of Medium Voltage Vacuum Circuit Breaker

As the wide use of vacuum circuit breakers in medium voltage field,the reliability of its operation is getting more and more concern.Vacuum circuit breakers are one of the main electrical appliances in high voltage switches and its performance affects the operation of the whole line.Due to the low requirements of power,high reliability and other advantages,the spring operating mechanism has been widely used in vacuum circuit breakers.The design of vacuum circuit breakers is mainly based on introduction and analogy.In practical project,the prototype in many cases is made to obtain the main performance by means of type test and routinely test.In this way it will cost much and the cycle is too long.According to the requirements of the spring operating mechanism of the medium voltage vacuum circuit breaker,this dissertation takes the spring operating mechanism of the medium voltage vacuum circuit breaker in ABB company as research object and established the systematic theoretical analysis of EL spring operating mechanism so as to calculate the average closing and opening speed.Meanwhile the simulation analysis and field test of EL spring operating mechanism are carried out to get the simulation result and test result.By contrast to the three results on average closing and opening speed,the feasibility and validity of theoretical analysis are verified with the comparative analysis.It is of important significance for the research design and motion characteristics of spring operating mechanism.Firstly from operating principle of EL spring operating mechanism,this dissertation analyses the operating principle of energy-storing mechanism,holding mechanism and actuator in detail.The basic motion characteristics of EL spring operating mechanism are also illustrated in dissertation.Secondly after simplifying the model of EL spring operating mechanism,it adopts equivalent method to get velocity ratio,equivalent mass and energy of closing and opening spring in the theoretical calculation.The closed position is selected as characteristic position.The energy of self-closing force should be considered in closing speed calculation and the energy of self-closing force and contact spring should be included in opening speed calculation.Kinetic energy law is applied to get average closing and opening speed after choosing suitable mechanical efficiency.Finally the simplified model of EL spring operating mechanism is imported into Adams software and the virtual prototype is established to obtain simulation result of closing and opening speed after setting the parameters.Besides,the field test of medium voltage vacuum circuit breaker equipped with EL spring operating mechanism is made to gain graph of closing and opening process.The actual closing and opening speed will be gotten by data processing.The feasibility and validity of theoretical analysis are verified with the comparison among three results.It can provides theoretical basis for the design,research and development of a series of medium voltage vacuum circuit breakers equipped with the spring operating mechanism.The prospect of further research work for the future is also included in this dissertation.