外文翻譯--異步電動(dòng)機(jī)的電氣故障診斷監(jiān)測(cè)系統(tǒng)（英文）

1、Mechanical Systems and Signal ProcessingMechanical Systems and Signal Processing 20 (2006) 953–960A current monitoring system for diagnosing electrical failures in induction motorsG.G. Acosta?, C.J. Verucchi, E.R. GelsoD

2、epartment of Electromechanics, Facultad de Ingenier? ´a–UNCPBA, Av. Del Valle, 5737, B7400JWI Olavarria, Buenos Aires, Grupo INTELYMEC, ArgentinaReceived 24 April 2004; received in revised form 19 August 2004; accep

3、ted 3 October 2004 Available online 23 November 2004AbstractInduction motors are critical components in industrial processes. A motor failure may yield an unexpected interruption at the industrial plant, with consequence

4、s in costs, product quality, and safety. Many of these faulty situations in three phase induction motors have an electrical reason. Among different detection approaches proposed in the literature, those based on stator c

5、urrent monitoring are advantageous due to its non-invasive properties. One of these techniques resorts to spectrum analysis of machine line current. Another non-invasive technique is the Extended Park’s Vector Approach,

6、which allows the detection of inter-turn short circuits in the stator winding. This article presents the development of an on- line current monitoring system that uses both techniques for fault detection and diagnosis in

7、 the stator and in the rotor. Based on experimental observations and on the knowledge of the electrical machine, a knowledge-based system was constructed in order to carry out the diagnosis task from these estimated data

8、. r 2004 Elsevier Ltd. All rights reserved.Keywords: Fault diagnosis; Induction motor; Current monitoringARTICLE IN PRESSwww.elsevier.com/locate/jnlabr/ymssp0888-3270/$ - see front matter r 2004 Elsevier Ltd. All rights

9、reserved. doi:10.1016/j.ymssp.2004.10.001?Corresponding author. Tel.: +54 2284 4510655; fax: +54 2284 4506628. E-mail addresses: gerardo.acosta@ieee.org, ggacosta@fio.unicen.edu.ar (G.G. Acosta), verucchi@fio.unicen.edu.

10、ar (C.J. Verucchi), egelso@fio.unicen.edu.ar (E.R. Gelso).is appropriate for the stator windings monitoring, as it will be shown. The proposed CMS uses a NationalTM data acquisition equipment and is programmed in LabView

11、TM. From the acquired current data and the motor features, the CMS estimates the slip and load percentage. Based on experimental observations and on the knowledge of the electrical machine, a knowledge-based system (KBS)

12、 was constructed in order to carry out the diagnosis task from these estimated data. The results of each diagnosis are outcomes in the CMS screen in the form of fault modes index. If necessary, a warning is given to put

13、the motor under new observations (i.e. to measure the rotor speed or to change the motor load), or even to verify the power distribution net balance. Experimental results are presented from an induction motor of 380 V, 7

14、.5 HP and 1000 rpm, especially designed for running under different failure circumstances. These results with a high degree of correct diagnosis show a right direction to explore.2. Fault detection from stator currents2.

15、1. Motor current signature analysisWhen there are broken or even fissured bars, the rotor’s impedance exhibits an unbalance. The immediate consequence of such an unbalance is the existence of inverse sequence currents. T

16、hese currents have a frequency that is equal to the product of the slip (s) and the supply frequency (f). They generate a magnetic field that turns counter motor rotation-wise. This magnetic field is called inverse magne

17、tic field or IMF. The speed of this IMF is given by the expression (1):or i ¼ ?sos; (1)where or i is the speed of IMF, s the slip and os the angular supply frequency. If translated to stationary co-ordinates, such a

18、 speed may be re-written asos i ¼ ?sos þ or ¼ ð1 ? 2sÞos; (2)where or is the rotor speed. The amplitude of IMF depends on two features. The first is the unbalance degree in the rotor circuit (num

19、ber of broken bars), and the second is the value of the current in the rotor bars. This last depends on the motor’s load state. In this way, the IMF originated in the rotor’s impedance unbalance produce harmonic currents

20、 of frequency ð122sÞf in the stator windings. These currents interact with the main magnetic field and set a torque over the rotor, which oscillates with a frequency of 2sf [18]. This pulsating torque provokes

21、an oscillation also in the rotor speed. The amplitude of this oscillation is a function of the motor’s load inertia. As a reaction of such speed perturbation, new currents arise in the stator at a frequency (172s)f. The

22、new current component at frequency (1–2s)f is superimposed with the original, and then modifies its amplitude. In this way, it is concluded that rotor faults in an induction motor, can be determined from the observation

23、of the sidebands in the stator current spectrum, in the neighbourhood of both frequencies given byf SB ¼ ð1 ? 2sÞf : (3)An example of the current spectrum of a motor with this fault is shown in Fig. 1.ARTI