Research Of Electromagnetic Mechanics Simulation Of A New DC Circuit Breaker

At present,battery power supply have been widely used in new energy generation,energy storage and scientific research for its stable discharge voltage and long duration.During the discharge process,DC circuit breaker is necessary for interruption of high DC current when the battery power supply is in circiut failure.Therefore,the research of DC circuit breaker with high voltage,large interruption current and high switching speed has become an urgent problem.A new type of DC breaker is presented in this paper,and the simulation and anlysis of the core part of breaker is carried out.The current conductor of the circuit breaker is broken with an electromagnetic repulsion produced by induced eddy current,which is activated in the results of the preliminary charged capacitor.Therefore,the breaker has the characteristics of large capacity,flexibility and high reliability.Firstly,by analyzing the principle and the action process of the breaker,the working process of the circuit breaker is introduced in detail.A plurality of physics modules including the electromagnetic field module,the structural mechanics module and the circuit module are involved in the process of shutdown.The finite element analysis and calculation of modules are performed in this paper,providing theoretical basis for subsequent simulation.Secondly,based on the theoretical research,the analytical model based upon the solution of Maxwell is built by the software COMSOL Multiphysics.The method of calculating the significant parameters including coil current,distribution of magnetic flux,magnetic force,tube deformation and their interactions is achieved by sequential mode,and the optimal parameters are determined by contrast.Thus,under the design of this parameter,the radial electromagnetic force received by the current conductor is calculated,and the stress it receives is compared with the breaking strength of the current conductor to verify the feasibility of the design.Meanwhile,the preliminary tentative analysis of the arc extinguishing is completed for the circuit breaker.Finally,on the basis of the simulation research,the experiment and the result analysis of the circuit breaker are carried out.The annealing aluminum tube and non-annealing aluminum tube were carried out respectively,which proved that the annealing aluminum tube was easier to fracture.The preliminary experimental results confirm that the design of the new type of DC breaker is feasible.Its total turn-off distance reaches 30 mm.Thus,the breaker meets the demand of the battery system for DC protection switch.