A Direct Electromagnetic Force Closed-Loop Control Strategy for a Contactor

For the first time, a direct electromagnetic force closed-loop control strategy for a contactor is proposed in this article. First, an electromagnetic force observer based on a neural network is designed according to a binary one-to-one mapping of the electromagnetic mechanism parameters to observe the real-time electromagnetic force. Then, the real-time spring reaction force is obtained by combining the observed electromagnetic force with the mechanical motion equation and the spring reaction equation. Finally, a constant force margin is added to the real-time reaction force as the reference curve, and the real-time observed electromagnetic force is used as the feedback; thus, direct electromagnetic force closed-loop control is realized through hysteresis regulation. This scheme can control the constant positive acceleration of the movable core in the dynamic process by taking only the constant force margin as the control target, which ensures the reliable action of the contactor and controls the total kinetic energy of the movable core to control the impact energy and inhibit the contact bounces. Therefore, the direct electromagnetic force closed loop can more accurately and directly realize the dynamic matching of the electromagnetic force and reaction force, which is of great significance to the optimization control of the contactor dynamic process.