Research on temperature and braking performance of water-cooled eddy current retarder

Trucks have the problems of frequent braking and long-term braking during long-slope transportation. As the temperature of the traditional eddy current retarder is as high as 500 °C during braking, the braking torque of the retarder is seriously degraded. According to the principle of eddy current braking and current thermal effect, this paper proposes an eddy current retarder in which both the stator and the excitation coil are water-cooled. The multi-field coupling and bidirectional data transmission model of stator temperature field, coil temperature field and transient electromagnetic field are established. The relationship between the braking torque and the working time is analyzed under continuous braking conditions, considering the stator temperature and the temperature of the excitation coil. It provides theoretical support for the optimal design of the retarder. A test prototype of a water-cooled eddy current retarder was manufactured, and a bench drag test was carried out. The calculation results show that the numerical simulation method of coupling between the stator temperature field, the coil temperature field and the transient electromagnetic field is adopted, and the simulation values of the braking torque is in good agreement with the experimental values.