基于扩展卡尔曼方法的无速度传感器直接转矩控制

A Speed-sensorless Direct Torque Control Based on the Extended Kalman

由于无速度传感器感应电机在农业生产、交通运输等方面的应用日益广泛,针对传统直接转矩控制(DTC)存在低频脉动和控制精度差等问题,提出利用扩展卡尔曼滤波器对感应电机控制系统进行状态估计的方法,从而实现无速度传感器直接转矩控制。首先分析应用于感应电机的扩展卡尔曼滤波(EKF)算法,设计了一种基于EKF的观测器,用于同时估计感应电机的转速和负载转矩,由此建立无速度传感器EKF-DTC控制系统。仿真实验结果表明,系统具有较强的鲁棒性。相比传统DTC控制,EKF-DTC控制系统在低频脉动抑制和随动控制性能上有明显改善。

Speed-sensorless induction motor is widely applied in agricultural production and transportation. In order to minimize the ripples and improve the inaccurate speed at low speed in direct torque control system,a novel state estimation algorithm,which is based on the extended kalman filter（ EKF）,was proposed for sensorless control of induction motor. The application of EKF in asynchronous motor was studied in this paper,and a EKF-based observer was designed to estimate the speed and torque. Finally a direct torque control system based on the extended kalman（ EKF-DTC） was constructed. Simulation results showed that the robustness of drive system is enhanced by the proposed algorithm. The results also indicated that the system EKF-DTC has achieved a significant improvement on the performance of the low-frequency ripple suppression and follow-up control compared with traditional direct torque control（ DTC） system.