Research On The Design Method Of The Electromagnetic Repulsion Mechanisms

The demand for power switch of power system is higher and higher with the development ofthe power system. In the medium voltage DC power system, the expected short current value isso big that the existing DC circuit breaker is difficult to breaking the short current, so the currentlimiting circuit breaker is needed. The requirement for the operate rapidity of the current limitingcircuit breaker is very high. The existing operation mechanism is difficult to meet therequirements, the electromagnetic repulsion mechanism based on the eddy current repulsiveforce becomes the research focus because of its prominent advantages on rapidity.The electromagnetic repulsion mechanism gets the attention and researching of scholarsboth at home and abroad for its advantages of simple structure, fast action and high reliability.This paper summarized the influencing factors and the calculating methods of theelectromagnetic force and puts forward some questions after reading a lot of related literaturesboth at home and abroad. First, lack of the design method and design process, second, lack ofbraker buffer design, third, lack of switching bounce analysis.Aiming at the above questions, the mathematical model of the electromagnetic repulsionmechanism had been established, and based on this, the design method and the design processhad been putted forward for the mechanism used in the medium voltage DC hybrid currentlimiting vacuum circuit breaker. The design result had been verified by the united simulation ofAnsoft Maxwell and Ansoft Simplorer. Then, the analysis and design of the opening and closingkeep and the braking buffer had been done. The overlarge brake bounce is prevented effectivelyby the collision buffer and limit device. Finally, the closing operation had been done usingADAMS and the simulation shown that there is no closing bounce.