Design And Analysis Of Stationary And Dynamic Characteristic For Permanent Magnet Contactor

As a electrical switch, the working principle of permanent magnet contactor, which has the advantages of no noise, energy saving and high reliability, is close and open by electromagnetic and maintaining by permanent magnet. The research on the design method, static analysis and dynamic analysis of the permanent magnet contactor will have very vast impacts on both theoretical endeavors and practical applications and boosting its broad application in industry. The main works are as follows.The 40A permanent magnet contactor is designed based on double E model monostable structure, and the magnetic circuit of the magnetic system is emphatically studied and designed on this basis. The components are selected according to the requirements of magnetic system, on which basis to design the control circuit of the permanent magnet contactor with the functions of over-voltage protection and under-voltage protection. The charge-discharge process of the capacitor in the process of switching closing is made by the simulation calculation of MATLAB.The main contents of the static and dynamic characteristics calculation about the monostability permanent magnet system are presented in this paper. Then the basic equation for solving the plane stability magnetic field, boundary value problem and the processing method of the permanent magnetic materials are introduced; the steps and formulas for solving the electromagnetic force and flux based on finite element and the concrete process and iteration scheme of the equations for solving the permanent magnet system and circuit mechanical movement based on Runge-Kutta are given in this paper; the process for solving the dynamic characteristics based on the electro-mechanical equation coupling iteration and the process for solving static data based on the finite element are established.The static characteristic, which includes the magnetic field distribution of the magnetic system under the permanent magnet only and the calculation analysis of the permanent magnet retention capacity are calculated by finite method. Dynamic characteristic, which includes the attraction characteristic, counterforce characteristics and the velocity and stroke of the dynamic iron core during the actuation-release process of the magnetic system are calculated and analysed. The magnetic system is reformed in the original structure, which put the permanent magnet on the dynamic iron core. The affects brought from restructing are described from the view of working point of the permanent magnet.The results of the calculation analysis show that the counterforce characteristics and the attraction characteristic of the designed 40A permanent magnet contactor combine reasonably, the permanent magnet maintains reliably and the switching closing times all maintain the requirements of the production. After transformation, the switching closing speed of the magnetic system is improved, the working point of the permanent magnet is better than that before transformation.