基于滑模观测器的永磁同步电机模型预测电流控制研究

针对永磁同步电机无位置传感器高动态性能控制问题,对传统矢量控制存在电流内环PI控制器对系统性能的影响以及传统滑模观测器中动态转子位置角估计不准、稳态转速估计不精确等观测器性能进行了改进,提出了一种基于改进滑模观测器的永磁同步电机模型预测电流控制方法。根据永磁同步电机在同步旋转坐标系下的数学模型,选择了电机d、q电流作为状态变量,利用前向欧拉法推导出永磁同步电机d、q轴电流的预测模型。通过实时评估价值函数选出使得下一时刻电流跟踪效果最好的电压矢量,将其对应的开关状态作用于逆变器。同时,推导表贴式永磁同步电机的滑模观测器模型并对其观测出的转子位置角和转速进行补偿,得到较为精确的估算值。最后将算法在Matlab/Simulink进行了仿真试验。研究结果表明:所提出的控制方法动态性能好、稳态精度高。

Research on model predictive current control of PMSM based on sliding mode observer

Aiming at the sensorless high dynamic performance control of permanent magnet synchronous motor (PMSM), the influ-ence of current PI controller on the performance of traditional vector control system and the inaccuracy of the estimation of rotor position angle and rotor speed in the traditional sliding mode observer (SMO) were improved. A model predictive current control (MPCC) method for PMSM based on improved SMO was proposed in this paper. According to the mathematical model of PMSM in the synchronous rotating coordinate axis, the motor d, q current were selected as the state variables to deduce the prediction model ofd, q current with forward Euler. By evaluating the cost function in real time, the voltage vector which has a perfect current track-ing effect of the next moment was selected to acts on the inverter with its switching state. Moreover, the sliding mode observer model of surface mounted permanent magnet synchronous motor (SPMSM) was derived, and the rotor position angle and speed that observed by SMO were compensated in this paper, which would obtain the accurate estimation value. The proposed algorithm was tested in Matlab/Simulink. The results indicate that the proposed control method has nice dynamic performance and high steady-state accuracy.