共查询到19条相似文献,搜索用时 140 毫秒
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在基于转子磁链模型参考自适应理论的基础上,给出了一种参考模型和可调模型交互式的模型参数自适应(MRAS)方法,使系统能在电机转速和定子电阻辨识之间相互切换.该方法消除了纯积分和电机漏感对算法的影响,电机的低速性能得到了改善;同时,对定子电阻进行在线辨识,从而得到准确的转速观测结果,也能近似地辨识转子电阻.计算机仿真结果证明了该方法的有效性. 相似文献
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针对感应电机无速度传感器矢量控制下的速度辨识问题,设计了一种基于扩展状态观测器的闭环转子磁链观测器(CESO),并提出以其作为参考模型的模型参考自适应(CESO-MRAS)转速辨识方法。该磁链观测器将模型中不确定部分进行状态扩展并反馈补偿,是一种闭环观测器,因而对电机转子电阻变化以及外部扰动具有良好的鲁棒性,克服了传统电压转子磁链模型的纯积分和低速区的电压降问题。通过与传统MRAS的仿真比较研究,在转子电阻和转矩的大范围变化低速区,该算法能显著提高矢量控制系统的速度动态辨识能力和转矩抗扰能力。仿真和实验结果验证了该方法的正确性和有效性。 相似文献
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介绍了一种能在线补偿定转子电阻的基于自适应观测器的感应电机转速估计方法.该转速估计方法只需检测定子电压电流作为输入,利用观测器观测出转子磁链和定子电流,并利用定子电流误差和转子磁链观测值辨识出转速、定子电阻和转子电阻,并反馈于观测器,确保电机转速估计对参数变化的鲁棒性.仿真及实验结果表明,此方法估计的速度能应用于无速度传感器矢量控制系统,并具有较好的辨识精度和鲁棒性. 相似文献
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无速度传感器感应电机改进转子磁链观测器 总被引:2,自引:0,他引:2
针对感应电机无速度传感器磁场定向控制系统,提出一种基于电压模型的改进转子磁链观测方法.为了有效抑制反电动势积分环节所存在的直流偏移和积分饱和问题,采用一个截止频率可根据输出频率进行自调整的低通滤波器来代替传统电压模型磁链观测器中的反电动势积分环节.然而低通滤波器的引入将会产生磁链幅值和相位的观测误差,从而导致在低速运行场合中磁链观测性能显著下降,为了解决这一问题,设计一个可以补偿磁链观测误差的补偿器.通过11kW感应电机无速度传感器矢量控制系统对所提出的改进转子磁链观测器进行了实验验证,结果证明了算法的有效性. 相似文献
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针对基于转子磁链模型参考自适应法的感应电机矢量控制系统性能受转子参数影响较大的问题,分析磁链观测器对转子参数的敏感性,提出了一种基于转子参数辨识和模糊控制的感应电机无速度传感器控制方法。该方法通过基于定子电流模型的模型参考模糊自适应系统来估计电机转速和转子参数,其中转速自适应率采用参数自调整模糊控制方法进行设计,并在线辨识转子参数,以提高转速和磁链的观测精度、减小参数摄动影响。仿真结果表明该系统具有较强的鲁棒性和自适应性。 相似文献
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This paper discusses the implementation and experimental results of a closed-loop rotor flux observer and model reference adaptive system (MRAS) of a direct field-oriented control (FOC) of an induction motor drive. The motor was supplied from a high-frequency (20 kHz) AC resonant link via a MOS-controlled-thyristor (MCT)-based bidirectional converter. Hardware and software implementations of the various motor control functions are presented. The closed-loop observer combines the current and voltage models via a speed-dependent gain (SDG). The current model was formulated to operate in the rotor reference frame and requires only an encoder angle and not the actual rotor speed for implementation. The closed-loop observer permits the use of a pure analog integrator to calculate an adequate stator flux. The use of an AC resonant link further complicated an all-digital calculation of the stator flux. The observer and adaptive controller were tested on a 400-Hz 2-hp induction motor for low and high speeds. The closed-loop observer showed sensitivity at low speeds to the rotor circuit time constant which attributed to the current model rotor flux estimation. At high speed, the closed-loop observer followed the voltage model rotor flux estimation attributes. The MRAS was able to improve the complete speed response by correcting the current model rotor flux observer for errors in estimation of its parameters 相似文献
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本文介绍了一种改进的定子磁链观测方法,并在此基础上设计了转速估算器。磁链观测器和速度估算器结合起来应用于无速度传感器的矢量控制系统。通过Matlab仿真试验,得到转速、转矩、定子电流及其磁链等的仿真波形。仿真结果验证了该控制方法具有较好的动态响应和较强的鲁棒性。 相似文献
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提出了一种新型异步电动机滑模变结构速度观测器,利用定子电流计算值与实际值的偏差来计算电动机的转速.该观测器由转子磁链观测、定子电流计算和滑模控制器3部分组成,其中转子磁链观测部分采用改进的电压模型,有效解决了传统电压模型固有的直流偏置误差和初始值积分误差问题,实现磁链的准确观测.最后,结合异步电动机无速度传感器的矢量控... 相似文献
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直接转矩控制永磁同步发电机相位自校正型定子磁链观测器 总被引:1,自引:0,他引:1
直接转矩控制永磁同步发电具有电磁转矩和直流电压输出动态响应快等优点,但这些优点的实现需要准确的定子磁链。实际发电机参数在一定范围内随工作点变化而变化,这就要求定子磁链观测器对这些参数变化具有很强的鲁棒抑制特性。该文提出一种新型定子磁链观测器,该观测器借助有效磁链概念计算出转子磁极位置角观测值,基于此将定子磁链电压模型和电流模型联系起来,无需转子速度信息;为了进一步降低观测的定子磁链相位误差,将观测的定子电流矢量与实际定子电流矢量乘积结果送给PI调节器,利用PI输出值对转子位置角观测值进行校正。实验结果表明,采用该文提出的定子磁链观测器在无需转子速度及参数辨识情况下,对电机参数变化及模拟量采样误差具有很强的鲁棒抑制特性,可以获得准确的磁链观测值,实现电磁转矩和直流发电电压的快速而平稳控制。 相似文献
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在异步电动机数学模型的基础上,介绍了一种改进的定子磁链观测方法,并在此基础上设计了转速估算器.磁链观测器和速度估算器结合起来应用于无速度传感器的矢量控制系统.通过Matlab仿真试验,得到转速、转矩、定子电流及其磁链等的仿真波形.仿真结果验证了该控制方法具有较好的动态响应和较强的鲁棒性. 相似文献
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G. R. Arab Markadeh J. Soltani 《Electrical Engineering (Archiv fur Elektrotechnik)》2006,88(6):485-496
A Direct torque and flux control design for a sensorless induction motor, following a Lyapunov-based stator flux observer
is presented. In this control scheme, the torque error signal and the amplitude of the stator flux reference vector are delivered
to a PI predictive controller. The predictive controller also uses information on the amplitude and position of the actual
stator flux vector and measured stator currents to determine the voltage command vector for space vector modulation inverter.
In addition, a conventional PI speed controller is used to generate the torque reference signal. Using the fifth order model
of the three-phase induction machines in a stationary two axes reference frame, a nonlinear stator flux observer is developed
in order to estimate the rotor speed, rotor and stator resistances simultaneously. The stability of this observer is proved
by Lyapunov theory. It is shown that if the persistancy of excitation condition is satisfied, the estimated quantities converge
to their real values. The effectiveness of the proposed control scheme is verified by computer simulation and experimental
results. 相似文献
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This article focuses on the design and analysis of a direct field orientation (DFO) approach based upon a closed-loop loop rotor flux observer. The approach is ideally suited for applications requiring both zero and very high (i.e., several times base) speed operation. Such applications are common in manufacturing automation where both zero speed position control and high traverse rates with controlled position trajectories are required. Examples include robot motion control systems as used for assembly and the more traditional machining center axis control. The quality of the proposed approach is largely based on the unique structure of its flux observer. The observer effectively combines the best accuracy attributes of rotor flux indirect (feedforward) field orientation (IFO) and stator flux DFO. The parameter sensitivity is similar to IFO at low and zero speeds and to stator flux DFO at high speeds. The closed-loop structure of the observer provides a smooth transition between two open-loop rotor flux observers referred to as the current and voltage models in a deterministic manner set by the closed-loop bandwidth (eigenvalues). The proposed DFO approach is analytically evaluated in comparison with both IFO and stator flux DFO. Experimental results verify the viability of this approach 相似文献