无传感器式交流电动助力转向系统直接转矩控制

永磁同步电动机驱动的电动助力转向系统已成为发展方向,为适应交流电动机特点,基于模糊规则的助力-回正特性,采用扩展卡尔曼滤波估算定子磁链与位置,利用直接转矩控制算法对助力电动机进行控制,以提高电动机响应速度与精度。参照国标对该系统的转向轻便性与回正性能进行了仿真,结果表明提出的系统在电动机助力后转向效果明显,方向盘平均操作转矩减小45%,转向轮回正时间缩短了50%。台架试验结果显示,系统动态响应快,能够很好地完成助力控制目标。

Direct Torque Control of Sensorless AC Electric Power Steering System

Electric power steering (EPS) system driven by permanent magnet synchronous motor (PMSM) has become the future trend of development. In order to adapt the characteristics of AC motor, dynamical-returnability characteristics based on fuzzy rules were designed. The extended Kalman filter (EKF) was introduced to estimate the stator flux and location, and the direct torque control (DTC) was adopted to control PMSM, so as to accelerate the response rate and precision. Referring to the national standard, simulation of this system was carried out on steering portability and return performance, the results show that the effect of the proposed system is significant under PMSM assisting, the steering wheel average operating torque is reduced by 45%, and the wheel self-turning time shortens 50%. Finally the bench test was experimented and shows that the whole system dynamic operates well and can fully complete the power control target.