基于负载扰动补偿的PMSM无传感器控制研究

Sensorless Control of PMSM Based on Load Disturbance Compensation

为提高永磁同步电动机中高速运行下无传感器控制的精度和稳定性,提出一种带有负载扰动补偿的PMSM无传感器控制策略。利用扩张观测器与锁相环结合对电机转速进行估计,为解决扩张观测器抗负载扰动性能差的问题,设计一个扰动观测器来估计负载转矩的大小,引入中间变量,避免了状态量的直接微分运算,最终将估计的负载转矩值转换成交轴电流对控制系统进行前馈补偿,从而减小电流脉动。在Simulink仿真环境下对所提出方法与经典滑模观测器方法进行比较,实验结果表明,所提方法可以大大提高电机转速的估算精度,改善系统动静态性能,减小负载扰动对系统稳定性的影响。

In order to improve the accuracy and stability of sensorless control of permanent magnet synchronous motor(PMSM) in medium and high speed operation, a sensorless control strategy of PMSM with load disturbance compensation is proposed. Expansion observer and phase-locked loop are used to estimate motor speed. In order to solve the problem of poor anti-load disturbance performance of the extended observer, a disturbance observer is designed to estimate the load torque, and an intermediate variable is introduced to avoid the direct differential operation of the state variables. Finally, the estimated value is converted into the quadrature current to compensate the feed-forward of the control system so as to reduce the current ripple. The proposed method is compared with the classical sliding mode observer method in Simulink simulation environment. The experimental results show that the proposed method can greatly improve the estimation accuracy of motor speed, improve the dynamic and static performance of the system, and reduce the impact of load disturbance on the stability of the system.