中文摘要：

研究了一种低电压大转矩无刷直流电动机控制系统设计方法。该系统以竞赛用纯电动汽车为背景，针对车载电池输出功率有限、电压较低的情况，提出了一种分段PWM占空比输出的算法，基于此算法可有效改善电机转矩输出，以满足不同的路况要求。实验表明，该方法能够使电机获得较大转矩，车辆达到了预定的速度与载重能力。

英文摘要：

The control system of motor with low voltage and high torque for electric vehicle（EV） was designed for the EV used for races, whose battery＇s voltage was low and output power was limited. The duty cycle was divided into several parts to get the various torques while wheels were on different types of surfaces. The result shows BLDCM can output high torque and the EV achieves the goal.