自励式双凸极构造电涡流液冷缓速器研究

Because the vehicle hydraulic retarder is expensive and its processing technique is complicated, its large-scale applications are difficult in China. Moreover the eddy current retarder is subject to severe decay of braking torque as temperature is increasing, easy burnout of excitation coils and high consumption of electric power. According to our progress in vehicle retarder for many years, we firstly present the self-excited double salient poles liquid cooling eddy current retarder at home and abroad. It totally changes the magnetic circuit structure of the eddy current retarder. The new type retarder consists of a stator with internal cooling channel that replaces the rotator of the eddy current retarder, and a rotator characterized with H-shape structure that the part near the stator is salient pole like gear. Unlike the eddy current retarder, the new type retarder only has one non-rotating excitation coil that is located within the retarder and is excited by the current from the internal three-phase permanent magnet generator. The new type retarder results in a significant improvement in structure and cooling, which greatly decreases the decaying of braking torque as heat is accumulating and eliminates the consumption of electric power from vehicle battery. This project intends to study on this new type retarder from three basic aspects. First aspect is the magnetic circuit structure, the efficiency of excitation, and the optimization of number, shape and other parameters of salient poles. The second is the heat transfer and the model coupled magnetic analysis with thermal analysis. The third is the establishment of the performance indexes system of the new type retarder and the electronic control method and so on. This project would update the retarders for buses; especially provide a new choice for large-scale applying of retarders for trucks in China.

针对液力缓速器工艺复杂、价格高在国内难以大规模应用，以及传统风冷式电涡流缓速器制动力矩热衰退严重、易烧线圈且耗电多的缺点，在多年研究基础上，首次提出一种自励式双凸极构造电涡流液冷缓速器完整解决方案。该新型缓速器颠覆了传统电涡流缓速器的构造，其内含水道的定子代替毂式缓速器的转子，转子则为H型构造，但接近定子的部分为齿状凸极。它的励磁线圈只有一个，置于缓速器内腹且不旋转，励磁则由置于缓速器内部的三相永磁发电机提供电流。该缓速器构造简单且能够高效冷却，故工作时本体温度低，制动力矩热衰退大幅度减小，也不需电瓶供电。本项目拟从三个方面对该新型缓速器进行基础性研究：一是深入研究其磁路分布、励磁效率，并对其凸极数及形状等参数进行优化设计；二是对磁热耦合传热模型进行深化研究；三是给出其性能评价指标，并探讨与整车匹配控制等问题。该研究有望为我国大客车缓速器的升级，尤其是大货车缓速器的大规模推广提供新途径。

针对液力缓速器工艺复杂、价格高在国内难以大规模应用，以及传统风冷式电涡流缓速器制动力矩热衰退严重、易烧线圈且耗电多的缺点，在多年研究基础上，首次提出一种自励式双凸极构造电涡流液冷缓速器（简称电液缓速器）完整解决方案。该缓速器包括制动系统、发电机系统和控制系统三部分。制动系统包括 H 型凸极结构的转子、内置水道的定子，线圈固定在定子内侧；内置发电系统采用无电刷结构的永磁同步发电机；控制系统采用功率驱动模块实时控制和调节励磁电流大小，从而控制制动力矩大小。研究了双凸极自励缓速器电磁场基本理论，建立了缓速器数学模型，并对其磁路和涡电流场进行了分析建模。运用电磁场专业仿真软件，对模型进行了数值模拟分析，得到了缓速器的磁路特点、涡电流场分布，同时研究并分析了材料电导率、励磁电流大小和磁路饱和程度对缓速器制动力矩的影响。得出了制动力矩对电导率、励磁电流的变化曲线。在上述理论分析的基础上，运用电机设计基本理论和缓速器设计基本原则设计了一台最大制动力矩1600N.m的双凸极自励式缓速器样机，通过台架实验验证和修正了设计理论，得到其自然特性和转速特性曲线，并探讨了与整车匹配控制等问题。. 在双凸极构造缓速器研究基础上，发现电液缓速器系列结构，具有共同特征，即“聚磁效应+横向磁通+水冷构造”。试制出了外转子缓速器、内嵌式缓速器和中置式缓速器样机，其中内嵌式构造具有转子转动惯量更小的优点，试制出了多台内嵌式坦克缓速器样机，测试表明性能优异。电液缓速器系列在国内做到了很好的市场推广。