Aiming at the problem that the large electromagnetic acceleration force fluctuation and the excessive peak acceleration force of the armature may be harmful to the sensitive loads, a new type of driving circuit of time-sharing triggering capacitors is proposed. The triggering unit consists of a capacitor and a thyristor, which is connected in parallel with previous thyristor in the driving circuit. The detailed working process is as follows: When the thyristor Th1 is triggered, the capacitor C1 charges the driving coil. When the acceleration force of the armature decreases to a certain extent, the thyristor Th2 is triggered, and the capacitor C2 exerts reverse voltage on the thyristor Th1 to turn off the Th1 and charges the driving coil.

The main content of this paper includes the following parts: firstly, the driving circuit of time-sharing triggering circuit capacitors is designed. Then, the influence of the changes of the capacitance value and the armature triggering position on the electromagnetic launch performance is analyzed to illustrate the feasibility of the proposed circuit. Finally, three modes of driving circuits are designed for comparison, and the calculation results show that: under the conditions of the same initial energy storage and the approximate muzzle velocity of the armature, compared with other circuit triggering modes, the time-sharing triggering circuit could effectively reduce the peak acceleration force and acceleration force fluctuation of the armature. 

Fig.1 The proposed circuit of time-sharing triggering capacitors

The proposed circuit can not only reduce the peak acceleration force and the acceleration force fluctuation, but also keep the acceleration within a range of slightly smaller than the maximum acceleration to allow the armature to reach the target speed faster, which is beneficial to the miniaturization design of the coilgun. Therefore, the proposed circuit has high engineering application value.

支持基金：

磁浮技术与磁浮列车教育部重点实验室开放课题基金

Foundation of Key Laboratory of Magnetic Suspension Technology and Maglev Vehicle, Ministry of Education

论文链接：

http://www.motor-abc.cn/djykzyy/article/abstract/20240602

推荐引用格式：

WANG Haojie, YAN Zhongming, LIN Feihong, WANG Yu. Design of External Circuit for Induction Coilgun with Low Acceleration Force Fluctuation[J].  Electric Machines & Control Application, 2024, 51(6): 12-19.

Wang Haojie, graduate student of the school of electrical engineering, Southwest Jiaotong University, majoring in pulse power and electromagnetic propulsion technology. Email: 863176326@qq.com

Yan Zhongming, Ph.D., researcher, doctoral supervisor. He has presided over more than 20 national projects, including the National High Technology Research and Development Program, JKW Key Project, Strategic Rocket Innovation Fund, Natural Science Foundation General Project, High-speed Rail Joint Fund, etc. He has published more than 50 SCI retrieval papers and applied for more than 10 invention patents. The main research directions: 1. Electromagnetic propulsion technology; 2. Wireless power transfer, electromagnetic energy collection and dump; 3. Metamaterial structure, magnetoelectric functional devices. Email: yzm@swjtu.edu.cn