共查询到17条相似文献,搜索用时 203 毫秒
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提出了一种基于信号注入的新型极低速异步电机无速度传感器矢量控制方法.该方法通过注入低频定子电流信号得到转子位置角度误差,并进而估计电机转速.该方法不依赖于异步电机的非理想特性,仅由基波模型就可实现极低速段的转速估计.此外,该方法还具有较强的电机参数鲁棒性.仿真及实验结果证明,基于低频信号注入的方法可以很好地实现异步电机在极低速段的无速度传感器矢量控制. 相似文献
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异步电机参数离线辨识改进算法 总被引:2,自引:0,他引:2
为实现变频调速系统的自运行(self-commissioning),提出了一种异步电机参数离线辨识的改进算法,该算法能直接辨识出与无速度传感器定子磁场定向矢量控制相关的大部分电机参数。利用直流实验辨识定子电阻,并通过分析逆变器的开关状态,得到直流实验的等效控制电路。采用单相交流堵转实验辨识定子总漏感和转子电阻,并通过分析异步电机相量图得到单相交流堵转实验稳定运行的工作条件。恒压频比空载实验辨识定子自感,对电机定子频率进行补偿以消除可能出现的定子电流振荡。利用直流侧电压和PWM占空比来重构定子电压,并根据电机电流极性补偿逆变器死区引起的电压误差。最后,在两台不同功率等级的异步电机上进行了参数辨识和无速度传感器定子磁场定向控制的实验研究。实验结果表明,参数辨识结果对直流侧电压不敏感,辨识得到的电机参数能满足无速度传感器矢量控制系统对电机参数准确性的要求。 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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《中国电机工程学报》2010,(15)
针对异步电机开环V/F控制系统低速性能差和轻载不稳定的问题,根据异步电机状态方程推导出一种新型电压矢量控制策略。该策略采用一种新颖的电压提升方法对电机定子电阻压降进行补偿,使电机磁链幅值保持恒定,并基于系统不稳定状态的深入分析,提出了一种提高系统稳定性的方法。在极低速情况下,通过对电机转矩进行提升以及对滑差进行补偿,使系统的低速性能和转速精度得到明显改善。与无速度传感器矢量控制算法不同的是,该文提出的方法是根据定子电压矢量定向对电流进行解耦,其不需要复杂的磁链观测运算,容易实现。实验结果表明,采用此方法在0.1Hz满载情况下,电机能平稳运行。该系统的低速性能和转速精度得到了明显提升,并且系统的空载振荡得到了抑制,在整个工作范围内都能平稳运行。 相似文献
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一种改进异步电机直接转矩控制系统性能的方法 总被引:3,自引:1,他引:2
针对异步电动机直接转矩控制系统低速时转矩脉动大,定子磁链内陷和电流畸变等问题,提出了一些改进措施.针对U-I模型计算磁链时直流分量造成积分漂移问题,采用具有幅值补偿环节的改进积分器算法取代纯积分环节克服积分漂移;针对传统的6区段电压矢量选择表中当定子磁链处于区段分界线附近控制性能差和未能充分利用电压矢量等缺点,采用细分优化的12区段选择电压矢量开关表来代替传统6区段电压矢量表,构成一种改进异步电机直接转矩控制系统性能的方法.仿真结果表明该方法可以明显改善磁链轨迹和转矩脉动,提高了控制系统的性能. 相似文献
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由于永磁同步电机在低速运行时,电机反电动势较小,因此采样通道的非线性导致的采样电压和电流中包含的直流偏置对电机反电动势观测的影响更为严重。针对这个问题,提出了一种基于超螺旋滑模观测器的永磁同步电机无速度传感器控制方法。首先,基于等效反馈的概念,设计了一种新的超螺旋滑模观测器,以提高低速时的无速度传感器控制精度;其次,详细分析了直流偏置对无速度传感器控制的影响,并且设计了一种基于二阶广义积分器的直流偏置抑制方法,从而进一步提高了无速度传感器控制精度;最后,通过6.6 kW永磁同步电机无速度传感器控制系统验证了所提控制策略的有效性。 相似文献
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Modified direct torque control method for induction motor drives based on amplitude and angle control of stator flux 总被引:1,自引:0,他引:1
Yuttana Kumsuwan Suttichai Premrudeepreechacharn Hamid A. Toliyat 《Electric Power Systems Research》2008
This paper proposes design and implementation of a direct torque controlled induction motor drive system. The method is based on control of separation between amplitude and angle of reference stator flux for determining reference stator voltage vector in generating PWM output voltage for induction motors. The objective is to reduce electromagnetic torque ripple and stator flux droop which result in a decrease in current distortion in steady-state condition. In addition, the proposed technique provides simplicity of a control system. The direct torque control is based on the relationship between instantaneous slip angular frequency and rotor angular frequency in adjustment of the reference stator flux angle. The amplitude of the reference stator flux is always kept constant at rated value. The system has been implemented to verify its capability such as torque and stator flux responses, stator phase current distortion both during dynamic and steady state with load variation, and low speed operation. 相似文献
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为解决异步电动机直接转矩控制(direct torque control,DTC)中低速运行时定子电阻变化对系统性能影响较大的问题,提出了一种基于定子电阻辨识和无速度传感器的异步电机直接转矩控制模糊系统。其中定子电阻采用模糊神经网络进行辨识;电机转速采用基于转子磁链的模型参考自适应系统(model reference adaptive sys-tem,MRAS)法进行估计;同时采用三输入单输出的模糊控制器调节脉冲宽度调制(pulse width modulation,PWM)信号占空比的异步电动机直接转矩控制的策略,三输入变量为转矩误差、磁链幅值误差和磁通角。此策略即在传统异步电动机直接转矩控制的基础上,用模糊控制器代替传统DTC中的滞环比较器和空间电压矢量状态选择器来细分控制规则,最后控制逆变器的开关,以减小低速时转矩和磁链脉动,提高系统转矩响应速度。仿真结果表明该系统可减小转矩和磁链脉动,提高系统的鲁棒性和自适应性,改善系统的动、静态品质。 相似文献
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Drift- and parameter-compensated flux estimator for persistent zero-stator-frequency operation of sensorless-controlled induction motors 总被引:1,自引:0,他引:1
The performance of sensorless-controlled induction motors is poor at very low speed. The reasons are the limited accuracy of stator voltage acquisition and the presence of offset and drift components in the acquired signals. To overcome these problems, a pure integrator is employed for stator flux estimation. The time-variable DC offset voltage is estimated from the flux drift in a parallel stator model and used to eliminate the offset by feedforward control. Residual high-frequency disturbances are compensated by feedback flux amplitude control. A linearization of the pulsewidth-modulation inverter transfer function and an improved stator resistance estimation scheme further enhance the system performance. Experiments demonstrate high dynamic performance of sensorless control at extreme low speed and zero stator frequency. 相似文献
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Young-Real Kim Seung-Ki Sul Min-Ho Park 《Industry Applications, IEEE Transactions on》1994,30(5):1225-1233
A vector control of an induction motor by an estimated speed using an extended Kalman filter is proposed. With this method, the states are composed of stator current and rotor flux. The rotor speed is regarded as a parameter, and the composite states consist of the original states and the rotor speed. The extended Kalman filter is employed to identify the speed of an induction motor and rotor flux based on the measured quantities such as stator currents and DC link voltage. The estimated speed is used for vector control and overall speed control. Since the current control is performed at a synchronous rotating reference frame, the estimated speed information is also used for the reference frame transformation of the current controller. Computer simulations and experiments of the speed control have been carried out to test the usefulness of the speed estimation algorithm. The experimental results show that the performance of the speed estimation is very good 相似文献
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Hisao Kubota Kouki Matsuse Yukio Kataoka Hisayoshi Ohta 《Electrical Engineering in Japan》2000,133(1):79-86
The vector control method is widely used for induction machine drives. Recently, sensorless vector control for induction machines has been investigated and proposed. The speed range for the drives is limited to about 1:100 in industry. The main reason for this limitation is the inaccuracy of stator voltage measurement. The lower the rotor speed is, the lower the stator voltage. Therefore, it is difficult to detect the stator voltage accurately in the lower speed region, and difficult to control motor speed and motor torque precisely. This paper presents a method of improving the lower speed performance of sensorless vector controlled induction machine drives using offset compensation of stator voltage. The offset is compensated by using the fluctuation of the estimated rotor flux. The validity of the proposed method is verified by experimentation. © 2000 Scripta Technica, Electr Eng Jpn, 133(1): 79–86, 2000 相似文献
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