齿形线圈励磁的新型电涡流缓速器电磁特性

Study on Electromagnetic Characteristics of a Novel Eddy Current Brake Excited by Toothed Coils

针对重载车辆用快响应、易控电涡流缓速器功率密度低的问题,提出一种利用轴向凸起的齿形线圈构建三维磁路,并通过过励磁设计抑制去磁效应的新型电涡流缓速器。应用有限元技术,建立新型高能电缓与传统端面磁路、轴面磁路电缓稳态、似稳态电磁场计算模型,分析新型电缓的磁路、气隙磁密、电涡流分布和过励磁制动特性。结果表明,新型电缓电涡流分布在转子内表面整个轴向空间内,当转速小于3 500 r/min时,其制动扭矩明显高于另两种传统电缓,且过励磁设计能够有效提升新型电缓的制动性能,线圈电流密度提高至3倍时,制动扭矩增加0.65倍,能够为车辆紧急制动提供瞬时大扭矩,使车辆制动距离缩短30%。

To improve the power density of fast-response and easily controlled eddy current brakes for heavy-duty vehicles, the method of constructing a three-dimensional magnetic circuit by using axially convex toothed coils and overexcitation design technology are proposed. Based on the finite element method, the steady-state and quasi-steady-state electromagnetic field calculation models of the novel high-energy eddy current brake and two traditional eddy current brakes are established, and their magnetic circuit, air gap magnetic density, eddy current distribution and overexcitation braking characteristics are analyzed. The results show that the eddy current of the novel high-energy eddy current brake is distributed in the whole axial space on the inner surface of the rotor. When the speed is less than 3 500 r/min, its braking torque is significantly higher than the other two traditional eddy current brakes. And the overexcitation design can effectively improve the braking performance. Since the coil current density is increased to 3 times, the braking torque is increased by 0.65 times, which can provide instantaneous high torque for vehicle emergency braking and shorten the braking distance of the vehicle by 30%.