基于模型参考自适应控制系统原理(MRAS)设计了一种新型的速度磁链自适应观测器,它以定子电流和定子磁链为状态变量,把磁链观测和速度辨识结合在一起,可以将定子磁链观测值直接应用于直接转矩控制算法中,并实现了异步电机无速度传感器直接转矩控制系统。定义了李亚普诺夫函数,根据其稳定性理论确定了速度自适应律。利用SIMULINK中的库元件和S-function构建了异步电机无速度传感器直接转矩控制系统仿真模型,仿真实验结果表明提出的速度磁链自适应观测器对速度辨识快速而准确,算法比较简单,计算量小,便于在线实现。该系统具有较好的定子磁链和转速观测精度以及对定子电阻变化的鲁棒性,能改善低速时磁链畸变的程度和运行特性。
This paper designs a new speed-adaptive flux observer which based on model reference self-adapt control system theory.It used stator current and stator flux as state variable,the observation of flux and estimate of speed were proceeding at the meantime.The observed flux could be applied to direct torque control system.In this base the speed sensor less direct torque control emulation system was designed.The speed adaptive scheme of speed estimation was obtain utilizing Lyapunov's stability theory.Based on the element and S-function in SIMULINK,The simulation former of speed sensor less direct torque control system was set up.The emulate experiment results indicate that this system is perfect,such as the speed estimate is quick and nicety,The arithmetic is simple,all this is easy to implement on line.And also the system has preferably observe precision of stator flux and speed of motor and robust character of motor stator resistance variety,it can reduce the degree of flux aberration and run characteristic in the low gear.