阐述了异步电机电制动的控制策略；分析实际应用中低速电制动转矩出现偏差的原因，并通过MATLAB绘制出当定向角度出现偏差时给定转矩与实际转矩在三维空间中的比例关系。为解决低速电制动时由于转子磁场定向偏差引起电机转矩不准的问题，采用基于无功功率模型的转子时间常数自适应控制进行校正。试验结果表明该控制策略可以实现校正转子磁场定向偏差的功能，具有良好的动态性能，可以满足地铁列车的性能要求。

Low-speed electric brake control strategy of the induction motor is described. The cause of the torque deviation in low-speed electric brake in practical applications is analyzed. A three-dimensional surface plot of the ratio of the given torque to the actual torque is created by MATLAB when the rotor field orientation angle deviates. The torque of motor is inaccurate because the rotor field orientation deviates during low-speed electric braking. In order to solve the problem, the reactive power model based rotor time constant adaptive algorithm is adopted. The experiment demonstrates that the algorithm can correct the rotor field orientation deviation and has good dynamic performance. The performance meets the requirement of the metro.