[关键词]
[摘要]
在电机高速弱磁或过载要求高的情况下,需要通过脉冲宽度调制(PWM)的过调制运行提高直流母线电压利用率。基于磁链观测的无传感器永磁同步电机矢量控制(磁场导向控制,FOC)技术具有算法简单、易实现等优点,但在过调制的情况下电压限幅环节会引起磁链观测及转子位置角估算误差。为提高PWM过调制情况下系统的控制性能,对传统的FOC控制框图进行了改进,省去了电压限幅环节并利用由占空比计算的实际电压对定子磁链进行估算。MATLAB仿真验证了改进方法的有效性。研究结果表明:该方法充分利用PWM调制自有的限幅特性,既能简化控制算法又能提高磁链观测精度,具有较好的技术经济性能。
[Key word]
[Abstract]
In the case of high speed weak magnetic field or high overload requirements of the motor, it was necessary to improve the voltage utilization rate of DC bus through pulse width modulation (PWM) overmodulation operation. The sensorless permanent magnet synchronous motor (PMSM) vector control (field oriented control, FOC) technology based on flux observation had the advantages of simple algorithm and easy implementation, but the voltage limiting link in the case of overmodulation would cause the error of flux observation and rotor position angle estimation. In order to improve the control performance of the system under PWM overmodulation, the traditional FOC control block diagram was improved, which eliminated the voltage limiting link and caculated the actual voltage obtained from duty ratio to estimate the stator flux linkage. MATLAB simulation verified the effectiveness of this method. The results showed that the new method could make full use of the inherent limiting characteristics of PWM, which could not only simplify the control algorithm but also improve the accuracy of flux observation, and had good technical and economic performance.
[中图分类号]
TM 351
[基金项目]
上海市科学技术委员会科研项目(17DZ1201200)