电磁斥力机构结构应力分析与优化设计

Structural Stress Analysis and Optimization Design of Electromagnetic Repulsion Mechanism

电磁斥力机构以其极高的驱动速度良好满足高压直流断路器对机械开关及其操动装置的快速性要求,同时其巨大的驱动力对传动系统带来强烈的机械冲击。针对上述问题,该文基于ANSYS Workbench平台对斥力机构结构强度问题开展研究。首先,建立耦合电路、磁场和结构力场的斥力机构数值计算模型,仿真结果表明销钉、连杆和斥力盘均存在应力振荡现象,其中斥力盘倒角和销钉是结构强度的薄弱环节;然后,基于仿真模型,发现增大斥力盘厚度、倒角半径、圆台及连杆半径等参数可提高系统刚度和振动频率,降低斥力盘的振动幅值,减小各部件应力振荡周期及峰值;最后,在40.5k V机械开关中开展了结构参数优化前后的运动特性对比试验,优化后的传动系统及斥力盘的振动周期与幅值更小,动作延迟显著降低,验证了结构参数对振动特性的影响规律。所获得的数值计算方法及结构参数影响规律可用于指导机构设计。

The electromagnetic repulsion mechanism(ERM)satisfies the high-speed DC circuit breaker’s requirement for the rapidity of the mechanical switch operating mechanism with its high driving speed,but its huge operating force has a strong impact on the transmission system.Aiming at above problems,this paper studies the structural strength of ERM based on ANSYS Workbench.First,a numerical simulation model coupled with magnetic fields,solid mechanics and circuits is implemented.The results show that there are stress oscillations in the pin,connecting rod and armature,among which the chamfering of armature and pin are the weak links of structural strength.Then,based on the simulation model,it is found that as the armature thickness,chamfering radius,circular platform radius,and connecting rod radius rise,the frequency of displacement vibration and stress oscillation of each part increase,while the vibration amplitude and stress peak decrease.Finally,comparative tests are carried out before and after the structural optimization in 40.5 kV mechanical switch.The vibration period and amplitude of the optimized transmission system are smaller,and the action delay is reduced,which verifies the influence of structural parameters on vibration characteristics.The obtained numerical calculation method and rules of structural parameters can be used to guide the design of mechanism.