基于自抗扰控制器的异步电机矢量控制系统研究
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摘要
矢量控制技术已被广泛地应用于高性能异步机调速系统中。然而,由于在实时控制中存在严重的外部干扰、参数变化和非线性不确定因素。基于精确电机参数的准确解耦很难实现,并且磁通和转矩的动态性能也受到严重的影响。
为了实现高性能异步电机调速系统,本文提出了把自抗扰控制融合到矢量控制中的策略,设计了基于自抗扰的闭环控制器、转子磁链观测器和转速辨识三部分组成。
转速环和电流环控制器直接影响矢量控制系统的动态性能。在保持控制性能的前提下,本文应用自抗扰控制ADRC理论,处理转速与电流方程中的未知外扰和模型耦合项,并设计了相应的控制器。该控制器设计为一阶结构,简化了模型结构,降低了计算量,大大提高了ADRC的实用性。
转子磁链观测是矢量控制的关键,为了消除转子电阻摄动对磁链观测的影响。本文提出了一种基于模型补偿扩张状态观测器(ESO)的转子磁链观测器,将转子电阻摄动视为系统的模型扰动,采用ESO加以观测和补偿,大大提高了观测器的观测精度。
另外,本文提出了基于ESO的转速辨识算法,利用自抗扰控制系统的已有结构,从ESO的未知模型观测结果中提取转速信息,实现了无速度传感器矢量控制。
仿真结果表明,相对于经典PID控制器,自抗扰控制器在较宽的调速范围内具有更好的动态性能以及对负载扰动、电机参数变化都具有更好的鲁棒性。
The field oriented control technique is widely used in high performance motion control of induction motors. However, in real-time implementation, precise decoupling which requires accurate motor parameter can't be fully realized due to significant plant uncertainties such as external disturbances, parameter variations and plant nonlinear dynamics. This may deteriorate the dynamic performances of flux and torque significantly.
In order to obtain high performance induction motor drive systems, Active Disturbances Rejection Control (ADRC) for a field-oriented induction motor drive system is proposed in this dissertation, in which he close-loop controllers、the rotor flux observer and the speed identification t are three dominant parts.
The dynamic performance of a FOC system depends on its speed and current loop controllers. While same dynamic performance is kept ,ADRC technology is introduced into the controller design to deal with the influences of the unknown external disturbances and the coupling items in speed and current models, the first-order ADRC model is simplified and its computation load is reduced, thus the practicability of ADRC is greatly enhanced .
Rotor flux observation is a key step in implementation of a field-oriented control (FOC) system. In order to reject the influence of rotor resistance perturbation, a new rotor flux observer based on an Extended State Observer (ESO) with model compensation is proposed. The perturbation of rotor resistance is taken as a system model disturbance, which can be observed and compensated by ESO. As a result, the performance of rotor flux observer based on ESO compensation is improved to a great degree.
For the implementation of sensorless FOC, a speed identification algorithm is introduced on the basis of ESO. By means of the existing structure of ADRC system, speed information is picked up from the observation results of the unknown model in ESO.
The simulation and experiment results show that the controller ensures very good robustness and adaptability under modeling uncertainty and external disturbance, and it is concluded that the proposed controller produces better dynamic performance such as small overshoot and fast transient time than conventional PID controller in the overall operating conditions.
为了实现高性能异步电机调速系统,本文提出了把自抗扰控制融合到矢量控制中的策略,设计了基于自抗扰的闭环控制器、转子磁链观测器和转速辨识三部分组成。
转速环和电流环控制器直接影响矢量控制系统的动态性能。在保持控制性能的前提下,本文应用自抗扰控制ADRC理论,处理转速与电流方程中的未知外扰和模型耦合项,并设计了相应的控制器。该控制器设计为一阶结构,简化了模型结构,降低了计算量,大大提高了ADRC的实用性。
转子磁链观测是矢量控制的关键,为了消除转子电阻摄动对磁链观测的影响。本文提出了一种基于模型补偿扩张状态观测器(ESO)的转子磁链观测器,将转子电阻摄动视为系统的模型扰动,采用ESO加以观测和补偿,大大提高了观测器的观测精度。
另外,本文提出了基于ESO的转速辨识算法,利用自抗扰控制系统的已有结构,从ESO的未知模型观测结果中提取转速信息,实现了无速度传感器矢量控制。
仿真结果表明,相对于经典PID控制器,自抗扰控制器在较宽的调速范围内具有更好的动态性能以及对负载扰动、电机参数变化都具有更好的鲁棒性。
The field oriented control technique is widely used in high performance motion control of induction motors. However, in real-time implementation, precise decoupling which requires accurate motor parameter can't be fully realized due to significant plant uncertainties such as external disturbances, parameter variations and plant nonlinear dynamics. This may deteriorate the dynamic performances of flux and torque significantly.
In order to obtain high performance induction motor drive systems, Active Disturbances Rejection Control (ADRC) for a field-oriented induction motor drive system is proposed in this dissertation, in which he close-loop controllers、the rotor flux observer and the speed identification t are three dominant parts.
The dynamic performance of a FOC system depends on its speed and current loop controllers. While same dynamic performance is kept ,ADRC technology is introduced into the controller design to deal with the influences of the unknown external disturbances and the coupling items in speed and current models, the first-order ADRC model is simplified and its computation load is reduced, thus the practicability of ADRC is greatly enhanced .
Rotor flux observation is a key step in implementation of a field-oriented control (FOC) system. In order to reject the influence of rotor resistance perturbation, a new rotor flux observer based on an Extended State Observer (ESO) with model compensation is proposed. The perturbation of rotor resistance is taken as a system model disturbance, which can be observed and compensated by ESO. As a result, the performance of rotor flux observer based on ESO compensation is improved to a great degree.
For the implementation of sensorless FOC, a speed identification algorithm is introduced on the basis of ESO. By means of the existing structure of ADRC system, speed information is picked up from the observation results of the unknown model in ESO.
The simulation and experiment results show that the controller ensures very good robustness and adaptability under modeling uncertainty and external disturbance, and it is concluded that the proposed controller produces better dynamic performance such as small overshoot and fast transient time than conventional PID controller in the overall operating conditions.
引文
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[10]K.A.Nigim and G.T.Heydt.Power quality improvement using integral-PWM control in an AC/AC voltage converter[J].Electric Power Systems Research,2002.63(1):65-71.
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[13]杨耕,陈伯时.交流感应电动机无速度传感器的高动态性能控制方法综述[J].电气传动,2001(3):3-8
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[26]韩京清,黄远灿.二阶跟踪-微分器的频率特性[J].数学的实践与认识,2003,33(3):71-74.
[27]韩京清.非线性PID控制器[J].自动化学报,1994,20(4):487-490.
[28]韩京清.一种新型控制器NLPID[J].控制与决策1994,9(6):401-407.
[29]韩京清.利用非线性特性改进PID控制率[J].信息与控制,1995,24(6):356-363.
[30]刘丁,刘晓丽,杨延西.基于遗传优化自抗扰控制器的机器人无标定手眼协调[J].机器人,2006,28(5):510-514.
[31]熊治国,孙秀霞,胡孟权.自抗扰控制器在超机动飞行快回路控制中的应用[J].控制与决策,2006,21(4):477-480.
[32]高龙,韩俊生.李崇坚等.非线性鲁棒自抗扰控制器在电力系统中的应用[J].清华大学学报,2000,40(3):27-29.
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