Research On Electro Magnetic Force Actuator Of 126kV Vacuum Circuit Breaker

With the rapid development of the socio-economic level,users have put forward new requirements for the power supply stability of the power grid.As one of the most important devices in the system,the high voltage circuit breaker is responsible for the rapid removal of the fault.According to the difference arc extinguishing media,the high-voltage circuit breaker can be divided into SF₆ circuit breaker and vacuum circuit breaker.In recent years,with the improvement of people's awareness of green power supply,the vacuum circuit breaker with more environmental protection and longer service life will develop towards higher voltage levels.On the basis of the manufacturing technology and the processing precision of the arc extinguishing chamber,the 126kV single break vacuum interrupter has been developed successfully.Therefore,as the core of the high voltage circuit breaker,a long stroke and large output actuator is required to match the 126kV single break vacuum interrupter.The permanent magnetic actuator is the most widely used electro-magnetic actuator,but due to its demagnetization characteristics,it can not be used in circuit breakers with long stroke.The Electro Magnetic Force Actuator,as a new type of actuator with the ampere force driving,has the advantages of simple structure,stable performance,powerful output and long stroke.Thus,this paper proposed and designed a new type of long stroke EMFA for 126kV single break vacuum circuit breaker,which is also the first EMFA applied to 126kV voltage level.In order to meet the requirements of 126kV vacuum circuit breaker for actuator,the EMFA designed in this paper needs to meet the design requirements of small volume,large output,small control current and rigid speed greater than 3m/s.In previous studies,most of the optimization design of EMFA is qualitatively analyze the factors affecting its characteristics,and not quantitatively determining its parameters while designing a complete product.Ansoft Maxwell simulation software was used to simulate the structural parameters of the 126kV EMFA,and the closing force of the EMFA was improved by changing the arrangement of auxiliary permanent magnets and the thickness of air gap when the volume was as small as possible.And by increasing the closing force makes opening speed at the separating instant of contact of the EMFA improved significantly and meet the current control design requirements;The influence of the electrical parameters such as charging capacitance and driving coil turns on the dynamic characteristics of the EMFA was analyzed,and on this basis,the parameters were selected.The simulation results show that the EMFA of 126kV single break vacuum circuit breaker designed in this paper has good operation characteristics and meets the characteristic requirements of 126kV vacuum circuit breaker.Based on the simulation,a new type of 126kV EMFA prototype has been developed,the mechanism has been debugged and bouncing,and finally passed the type test.The test shows that the 126kV EMFA designed in this paper has good action characteristics and has a high consistency with the simulation results.At the end of the paper,on the basis of the existing problems,two different types of EMFA model are proposed,which provides more possibilities for the development of the EMFA.