Optimal Design of Electromagnetic Repulsion Mechanism Based on NSGA-II Algorithm

The electromagnetic repulsion mechanism is widely used as the operating mechanism of DC circuit breaker. In the DC breaking scenario, the action time of the electromagnetic repulsion mechanism is required to break to the full opening distance within 2ms as much as possible, while ensuring a long service life. In this paper, the basic principle of electromagnetic repulsion mechanism is analyzed firstly, and then the simulation model of "coil-repulsion disc" type electromagnetic repulsion mechanism is built by using finite element software to analyze six important parameters (number of turns of coil, coil height, coil width, repulsion disc height, energy storage capacitance capacity and charging voltage). Finally, the parameters of the electromagnetic repulsion mechanism are optimized based on NSGA-II algorithm with the displacement and coil current of 2ms as the optimization target. The simulation results show that when the coil is 36 turns, the coil height is 7.75 mm, the coil width is 1.8 mm, the repulsion disc height is 8.35 mm, the storage capacitor capacity is 8000μF, and the charging voltage is 1100 V, the 2ms motion displacement of the electromagnetic repulsion mechanism increases from 11.68 mm to 12.56 mm compared with the initial design, and the coil current decreases from 6830A to 5580A, which can improve the opening speed and extend the life.