异步电机无速度传感器控制的Holtz型磁链观测器性能分析

Pefrormance analysis of holtz flux observer in speed-sensorless induction motor drive

针对异步电机无速度传感器控制中,电压型磁链观测器低速性能较差的问题,研究一种具有较好低速性能的电压型磁链观测器——Holtz型磁链观测器.基于线性化理论建立该观测器的小信号模型,得出观测器反馈系数与观测器稳定性和动态响应之间的关系.进一步分析观测器输入存在误差的情况下,反馈系数对磁链观测结果的影响.基于对观测器综合性能的分析,提出一种自适应的反馈系数设计方法.针对2.2kW的异步电机,分别在Matlab仿真平台和基于Dspace的实验平台上进行了观测器输入存在误差的仿真和实验.结果表明:当观测器阻尼系数取在1.0附近,也即反馈系数按同步角频率的2倍取值时,可以获得最佳的观测效果,并且在高速和低速下均能获得良好的动态和稳态性能.

For the speed-sensorless control of induction motor this work studied a kind of voltage model flux observer with good performance at low speed, which was presented by J. Holtz. A small signal model was established based on the linearized theory. Then the relationships between the feedback factor and the observer＇s performance, stability and dynamic response, were obtained. The influence of the input error on the flux observation was also analyzed. Considering various aspects of the observers＇ performance, a new self-adaptive design method of feedback factor of the observer was developed. On the Matlab-based simulation platform and Dspace-based experiment platform, simulations and experiments for a 2.2 kW in- duction motor when the observer inputs have errors were carried out. The results show that. when the damping coefficient is set near one or keep the feedback factor twice of the synchronous frequency, the flux observer can achieve the best effect and perform well at both high and low speed.