Article

Detection of Eccentricity Faults in Induction Machines Based on Nameplate Parameters

Dept. of Electr. & Comput. Eng., Univ. of Victoria, Victoria, BC, Canada
IEEE Transactions on Industrial Electronics (Impact Factor: 6.5). 06/2011; 58(5):1673 - 1683. DOI: 10.1109/TIE.2010.2055772
Source: IEEE Xplore

ABSTRACT

Eccentricity-related faults in induction motors have been studied extensively over the last few decades. They can exist in the form of static or dynamic eccentricity or both, in which case it is called a mixed eccentricity fault. These faults cause bearing damage, excessive vibration and noise, unbalanced magnetic pull, and under extreme conditions, stator-rotor rub which may seriously damage the motors. Since eccentricity faults are often associated with large induction machines, the repair or replacement costs arising out of such a scenario may easily run into tens and thousands of dollars. Previous research works have shown that it is extremely difficult to detect such faults if they appear individually, rather than in mixed form, unless the number of rotor bars and the pole-pair number conform to certain relationships. In this paper, it is shown that the terminal voltages of induction machines at switch-off reveal certain features that can lead to the detection of these faults in individual form, even in machines that do not show these signatures in line-current spectrum in steady state, or to the detection of the main contributory factor in case of mixed eccentricity.

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    • "cases for them other induction motor quantities help to detect signatures produced by the different faults such as stray flux and vibrations [14]. Many research works head to use others induction motor quantities to detect SE fault signatures such air gap magnetic flux density [13]-[15], terminal voltages of induction machines at switch-off [5]. "
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    ABSTRACT: Unfortunately, motor current signature analysis (MCSA) cannot detect the small degrees of the purely static eccentricity (SE) defects, while the air-gap magnetic flux signature analysis (FSA) is applied successfully. The simulation results are obtained by using time stepping finite elements (TSFE) method. In order to show the impact of magnetic saturation upon the diagnosis of SE fault, the analysis is carried out for saturated induction motors. The index signatures of static eccentricity fault around fundamental and PSHs are detected successfully for saturated motor.
    Full-text · Article · Aug 2015
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    • "where í µí±“ is fundamental frequency, í µí±˜ is positive integer number, í µí±“ í µí±Ÿ is the rotational frequency (speed) of motor (Hz), í µí± is the slip, and í µí± is the pole pair number. Meanwhile, the high-frequency components related to static eccentricity are specified in a compact form by the following equation [34] "
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    ABSTRACT: This paper is dedicated to investigating static eccentricity in a three-phase LSPMSM. The modeling of LSPMSM with static eccentricity between stator and rotor is developed using finite element method (FEM). The analytical expression for the permeance and flux components of nonuniform air-gap due to static eccentricity fault is discussed. Various indexes for static eccentricity detection using stator current signal of IM and permanent magnet synchronous motor (PMSM) are presented. Since LSPMSM is composed of a rotor which is a combination of these two motors, the ability of these features is evaluated for static eccentricity diagnosis in LSPMSM. The simulated stator current signal of LSPMSM in the presence of static eccentricity is analyzed in frequency domain using power spectral density (PSD). It is demonstrated that static eccentricity fault generates a series of low frequency harmonic components in the form of sidebands around the fundamental frequency. Moreover, the amplitudes of these components increase in proportion to the fault severity. According to the mentioned observations, an accurate frequency pattern is specified for static eccentricity detection in three-phase LSPMSM.
    Full-text · Article · Nov 2014 · Mathematical Problems in Engineering
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    • "Consequently, indicators of mixed RE overall level have been tried. Separate detection of SRE and DRE by using terminal voltage analysis at the electrical machine switch-off is reported in [19], and detection of RE in the presence of load torque oscillations is reported in [21]. The external flux is used in [22], where a DRE-related slip-frequency signature is detected by an axial coil. "
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    ABSTRACT: The fault diagnosis of rotating electrical machines has received an intense amount of research interest during the last 30 years. Reducing maintenance costs and preventing unscheduled downtimes, which result in losses of production and financial incomes, are the priorities of electrical drives manufacturers and operators. In fact, both correct diagnosis and early detection of incipient faults lead to fast unscheduled maintenance and short downtime for the process under consideration. They also prevent the harmful and sometimes devastating consequences of faults and failures. This topic has become far more attractive and critical as the population of electric machines has greatly increased in recent years. The total number of operating electrical machines in the world was around 16.1 billion in 2011, with a growth rate of about 50% in the last five years [1].
    Full-text · Article · Jun 2014 · IEEE Industrial Electronics Magazine
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