Research on Electrical Contact Characteristics of Brush-Rail Device With Transient Large Current

An excellent electrical contact state is necessary to ensure safe and stable operation of the system. Therein, contact resistance and arc ablation are essential indexes for estimating the contact state. In view of the characteristics of brush-rail device with transient large current for AC electromagnetic propulsion, a contact resistance model and the concept of arc ablative trigger boundary are proposed in this paper. Firstly, an equivalent circuit model is developed based on structural properties of brush-rail device. Then, the corresponding contact resistance model is established considering the contact pressure, amplitude and frequency of current, sliding velocity and consecutive run times. In addition, the main affecting factors of arc ablation are analyzed and the p-v parameters of arc ablation boundary are determined. Finally, the contact resistance and arc ablative trigger boundary of the brush-rail device are tested on a rotating transient large current experimental platform, which proves the correctness of the proposed method.