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基于定子电流监测方法的电机故障诊断 总被引:1,自引:0,他引:1
电机是一种复杂的旋转机械,其故障种类多而且难以辨别。为了对小功率异步电机的常见故障进行正确快速地诊断,采用小波分析技术对几种常见故障所引起的定子电流变化进行了多分辨率分析。从能量分布的角度出发,快速且较为准确地诊断出电机故障。诊断效果表明,小波分析是对电机故障进行定子电流诊断的有效方法,同时为电机故障在线实时诊断提供了理论依据。 相似文献
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双馈风力发电机轴承的状态监测和早期故障诊断可以及时发现轴承故障,有效地降低风电场的运行和维护费用.首先用加速度传感器采集轴承振动信号,然后用两种方法进行特征信号分析:一是对信号进行经验模式分解,仅提取第一模态函数做Hilbert变换,从而根据包络图判断轴承的早期故障;二是对信号进行预处理,滤去与轴承故障无关的主要分量,再采用小波滤波器提取微弱的故障信号,进而根据故障指标的数值来判断.最后对这两种方法对比研究,试验结果表明,方法2可以更加有效地诊断出早期故障,具有一定的工程应用价值. 相似文献
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为了突出故障早期的故障特征信息,避免复杂算法,实现故障早期状态在线监测,提出定子电流二次方法(流方)的笼型异步电机转子复合故障检测。定子电流经过二次方后转移和放大了定子电流中的故障信号,由于转子断条和气隙偏心的故障特征频率在频谱分布上的差距,转子复合故障得到分离和辨识。同时比较了单相流方和三相总流方对复合故障的诊断效果。复合故障时,流方的故障频率不是单一故障频率的直接累加,还包括两故障频率所引起的交叉干扰项。实验表明,随着断条数的增加,复合故障中表征断条的故障特征分量的幅值增加,有利于故障程度的量化和诊断系统的建立。 相似文献
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针对电机定子绕组匝间短路故障,提出了基于递归小波神经网络(RWNN)的故障在线诊断方法。该方法采用两个RWNN监测匝间故障,一个用于估算故障的严重度,另一个用于确定故障匝数。针对RWNN的训练,研究了Levenberg-Marquardt(LM)学习算法,以减少训练中的计算量,确保网络模型的快速收敛。根据此方法,设计了试验系统,试验结果表明,基于RWNN的诊断模型可精确确定短路故障匝数,与前馈神经网络(FFNN)相比,能更有效地监测匝间短路故障的缓慢变化情况。 相似文献
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This paper presents a novel method for detecting stator winding inter-turn short circuit fault in a three-phase induction motor by vibration signature analysis using non-electrical contact type microelectromechanical systems (MEMS) accelerometer. The present work detects inter-turn short circuit by vibration analysis in a three-phase induction motor running under different load conditions. Theoretical analysis of stator winding under inter-turn short circuit condition has been presented. Experimental investigations have been carried out to detect inter-turn short circuit fault by vibration signature analysis using a MEMS accelerometer with three-phase induction motor operating under different conditions. The spectral analysis of motor vibration has been carried out using radix-2 decimation in time fast Fourier transform algorithm. The appearance of particular characteristic frequency components in vibration spectrum indicates stator winding inter-turn short circuit faults. The experimental results are found to closely match with the theoretical values, indicating that MEMS accelerometers can be successfully employed for the detection of stator winding inter-turn short circuit fault in induction motors. 相似文献
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《Industry Applications, IEEE Transactions on》2009,45(3):911-920
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Adaptive digital f ilters have been shown to be useful in reducing the power of harmonic noise in distribution line communication systems. Many DLC systems currently in use employ hard limiters to reduce this type of noise prior to detection of the signal. This research shows that the adaptive noise cancellation filter can be used effectively in tandem with hard limiters. The optimal, limit of the limiter is determined in the cases of the presence and absence of the adaptive noise canceller. 相似文献
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Blodt M. Chabert M. Regnier J. Faucher J. 《Industry Applications, IEEE Transactions on》2006,42(6):1454-1463
This paper examines the detection of mechanical faults in induction motors by an original use of stator current time-frequency analysis. Mechanical faults lead generally to periodic load torque oscillations. The influence of the torque oscillations on the induction motor stator current is studied using an analytical approach. The mechanical fault results in a sinusoidal phase modulation of the stator current, which is equivalent to a time-varying frequency. Based on these assumptions, several signal processing methods suitable for stator current signature analysis are discussed: classical spectral analysis, instantaneous frequency estimation, and the Wigner distribution. Experimental and simulation results validate the theoretical approach in steady-state operating conditions 相似文献
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提出了一种采用定子电流和扰动观测补偿的改进预测电流控制(PCC)算法。理论上永磁同步电机PCC具有优异的控制性能,但现实系统中离散采样延时与电磁参数时变等问题使得原理上基于模型的预测电流控制器的控制品质严重恶化。设计了龙伯格(Luenberger)状态观测器实现对定子电流与参数扰动的观测,并应用于补偿和改进经典的无差拍预测电流控制器。将观测到的当前时刻的定子电流替代当前时刻的采样电流用于反馈控制,以补偿采样延时;运行过程中电磁参数的变化使得模型参数失配,其影响以电压扰动的形式被观测出来,并补偿到预测控制输出的电压指令中。仿真和试验结果验证了所提方法的有效性。 相似文献
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通过用脉冲响应法在电机定子绕组上进行试验所得到的数据及其分析,对定子绕组的绝缘故障检测提出了一些看法。 相似文献
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通过直接相量法建立了三相同步电动机定子绕组接地故障的数学模型。以一台三相同步电动机为例,运用Ansoft语言的RMxprt/Maxwell 2D模块建立了仿真模型,仿真了三相同步电动机的突然单相接地、两相接地、三相接地故障情况,分别给出了三种故障的定子电流与转矩曲线,并对结果进行了分析。 相似文献
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介绍了笼型感应电动机定子故障的类型 ,分析了产生故障的可能原因 ,阐述了热应力、电应力、机械应力、环境应力等对电机绝缘系统的影响及故障的表现状态 ,提出了相应的解决措施和办法 ,有助于电动机的维护和剩余寿命的推算 . 相似文献