电动助力转向用无刷直流电机直接转矩控制方法研究

Research on Direct Torque Control Method of Brushless DC Motor for Electric Power Steering

结合EPS系统的功能特点,提出1种适用于汽车转向的无刷直流电机(BLDC)系统直接转矩控制(DTC)方法,以提升汽车转向系统的控制性能。从BLDC系统的转矩特性和磁链特性的关系入手,根据电机系统的转矩、磁链跟踪误差及定子磁链所处扇区号,查询预先规划的离线查找表(LUT),直接输出最优的电压空间矢量。并基于Matlab/Simulink仿真平台进行BLDC调速系统的仿真实验。结果表明,DTC方法可以对电磁转矩脉动进行有效控制,而且能大大提高BLDC的动、稳态驱动性能,提供了1种适用于电动助力转向EPS系统控制的新思路。

According to the functional characteristics of EPS system , this article proposes a brushless DC motor （ BLDC） direct torque control （ DTC） method which is suitable to the automobile steering to improve the control performance of the automobile steering system .Beginning with the relationship between the torque and flux linkage characteristics of BLDC system , and according to the motor system′s torque, flux tracking error and sector number of the stator , it is to search for the pre-planned offline lookup table （ LUT） and directly output the optimal voltage space vector .Finally, the experiment of BLDC control system is simulated based on the Matlab/Simulink simulation platform .The experimental results show that the DTC method can effectively control the electromagnetic torque ripple , and greatly improve the dynamic , steady driving performance of BLDC , and provide a new idea that is suitable for the EPS control of the electric power steering system .