本文旨在探討軸承故障偵測裝置之結構及其於軸承故障診斷之應用。此裝置含有磁鐵及線圈繞組，其中磁鐵置於原動機旋轉側，線圈繞組置於偵測裝置的固定側。本文採用原動機帶動旋轉側端的磁鐵，並以鋁製墊片偏移感應電動機或偵測裝置的位置，模擬實際軸承偏移之故障狀況，利用線圈的不同分布及感應電勢電壓信號以偵測軸承的軸向偏差、徑向偏差、轉速及磁場角位置。文中將採用同步旋轉座標系統交、直軸的電壓值，配合量測的平均值及其相對誤差值作標么化，並由故障條件的校正，作為軸承偏移故障的判斷依據。
本文將先以Maxwell軟體模擬偵測裝置的磁路及諧波失真特性，並模擬軸承徑向故障情形，以驗證本裝置之可行性。系統採用數位信號處理器TMS320F28035為偵測系統的核心，利用外部16位元的類比-數位轉換器，其積體電路編號為AD7606，可將偵測線圈之類比感測信號轉換為數位信號。其中，故障判斷策略及轉速、磁場角位置偵測之軟體編寫皆以C語言完成，並以警示燈顯示目前軸承是否已偏移至危險區。經評估後，故障偵測裝置選用線圈弧長為14.3mm(0.8倍節距)，以降低感應線圈的諧波含量。本系統的徑向偏移量為1.5mm以上時，則交、直軸徑向誤差標么值將超過0.37，在軸向偏移量為2.5mm以上時，其交、直軸軸向誤差標么值將超過0.56，如此可以判斷軸承偏移的故障情況。

This thesis presents a structure design of a bearing-fault detection device and its application to fault diagnosis. The fault detection device contains coil windings and magnets. The magnets and coil windings are placed on the rotating side and the fixed side of the fault detection device, respectively. In order to simulate actual bearing fault conditions, the system uses a motor to drive the rotating side of the magnets and adjusts the position of the motor or the fault detection device with aluminum pads. Through the winding distribution pattern and induced voltage, the fault detection device can detect rotor speed, rotor position , radial and axial error of the bearing. The voltage values of the quadratic axis and direct axis on the synchronous rotating frame are adopted and converted to per-unit values based on the average values of the measured voltage and corresponding error. Moreover, such voltage values are corrected according to the fault conditions and can be used to determine whether the bearing is faulty or not.
Simulation on the magnetic circuit of the detection device, harmonic distortion characteristics as well as radial bearing fault conditions with Maxwell software package is first conducted to validate the feasibility of the system. In this system, the digital signal processor TMS320F28035, is adopted as the measuring core, using an external 16-bit analog-digital converter (AD7606) which converts the voltage singals of the coil windings from analog to digital. The software of fault detection strategy, measurment of rotor speed and position are accomplished with C language to show whether the bearing is shifted to the dangerous zone according to warning lights. After completing estimation, the coil arc length of the fault detection device is determined to be 14.3mm, which is 0.8 times the full pitch. Thus the harmonic content of the induction coil can be reduced. When the radial displacement of the system is over 1.5mm, the per-unit radial error value of quadratic axis and direct axis will exceed 0.37. Meanwhile, when the axial displacement of the system is over 2.5mm, the per-unit radial error of quadratic axis and direct axis will exceed 0.56. Therefore, the fault condition of shifted bearing can be decided.

[1] P. Zheng, J. Zhao, J. Han, J. Wang, Z. Yao and R. Liu,
“Optimization of the magnetic pole shape of a permanent-magnet
synchronous motor,” IEEE Transactions on Magnetics, vol. 43, no.
6, pp.2531 - 2533, 2007.
[2] Z. Q. Zhu, Z. P. Xia, and D. Howe, “Comparison of halbach
magnetized brushless machines based on discrete magnet segments
or a single ring magnet,” IEEE Transactions on Magnetics, vol. 38,
no. 5, pp.2997 - 2999, 2002.
[3] Z. Q. Zhu, S. Ruangsinchaiwanich, D. Ishak, and D. Howe,
“Analysis of cogging torque in brushless machines having
nonuniformly distributed stator slots and stepped rotor magnets,”
IEEE Transactions on Magnetics, vol. 41, no. 10, pp.3910 - 3912,
2005.
[4] Z. Q. Zhu, S. Ruangsinchaiwanich, Y.Chen and D. Howe,
“Evaluation of superposition technique for calculating cogging
torque in permanent-magnet brushless machines,” IEEE
Transactions on Magnetics, vol. 42, no. 5, pp.1597 - 1603, 2006.
[5] C. S. Koh and J.-S. Seol, “New cogging-torque reduction method
for brushless permanent-magnet motors,” IEEE Transactions on
Magnetics, vol. 39, no. 6, pp.3503 - 3506, 2003.
[6] S. A. Saied, K. Abbaszadeh, S. Hemmati and M. Fadaie, “A new
approach to cogging torque reduction in surface-mounted
permanent-magnet motors,” European Journal of Scientific
Research, vol. 26, no. 4, pp.499-509, 2009.
[7] L. Chang, L. Fenglin, “Application of Wavelet Analysis in Fault
Detection of Cell Phone Vibration Motor,” IEEE Conference on
Informatics in Control, Automation and Robotics, pp. 473-476,
2009.
[8] J. Cusido, J.A. Rosero, J.A. Ortega, A. Garcia, L. Romeral,
“Induction Motor Fault Detection by using Wavelet decomposition
on dq0 components,” IEEE ISIE 2006, July 9-12, 2006, Montreal,
Quebec, Canada.
[9] M. Aktas, V. Turkmenoglu, “Wavelet-based switching faults
detection in direct torque control induction motor drives,”
Published in IET Science, Measurement and Technology, Received
on 12th December 2009, Revised on 18th July 2010, doi:
10.1049/iet-smt.2009.0121 .
[10] C. Chao-Ming, A. Loparo, “Electric fault detection for
vector-controlled induction motors using the discrete wavelet
transform,” Proceedings of the American Control Conference,
Philadelphia, Pennsylvania June, vol. 6, pp. 3297-3301, 1998.
[11] D.-M. Yang, “Wavelet-based bispectra for motor rotor fault
detection,” Eighth International Conference on Intelligent Systems
Design and Applications. vol. 1, pp. 603-607, 2008.
[12] D. Hanselman, “Brushless permanent magnet motor design,” The
Writers’ Collective, U.S.A., 2003.
[13] 許哲嘉，“永磁式同步電動機之參數量測”，國立台灣科技大學
電機研究所碩士論文，民國九十一年。
[14] M. Vieira, and C. Theys “Induction motors’ faults detection and
localization using stator current advanced signal processing
techniques,” IEEE Transactions on Power Electronics, vol. 14, no.
1, pp. 14-22, 2001.
[15] B. Stumberger, B. Kreca and B. Hribernik, “Determination of
parameters of synchronous motor motor with permanent magnets
from measurement of load conditions,” IEEE Transactions on
Energy Conversion, vol. 14, no. 4, pp. 1413-1416, 1999.
[16] M. A. Rahman and P. Zhoy, “Determinations of saturated
parameters of PM motors using loading magnetic fields,” IEEE
Transactions on Magnetics, vol. 27, no. 5, pp. 3497-3590, 1911.
[17] F. F. Bernal, A. G. Cerrada and R. Faure, “Determination of
parameters in interior permanent-magnet synchronous motors with
iron losses without torque measurement,” IEEE Transactions on
Industry Applications, vol. 38, no. 5, pp. 1265-1272, 2001.
[18] N. Urasaki, T. Senjyu and K. Uezato, “An accurate modeling for
permanent magnet synchronous motor drives,” IEEE conference
and Exposition on Applied Power Electronics, vol. 1, pp. 387-392,
2000.
[19] B. N. Mobarakeh, F. M. Tabar and F. M. Sargos, “On-line
identifications of PMSM electrical parameters based on decoupling
control,” IEEE Industry Applications Conference, vol. 1, pp.
266-273, 2001.
[20] A. H. Wijenayake and P. B. Schmidt, “Modeling and analysis of
permanent magnet synchronous motor by taking saturation and
core loss into account,” IEEE International Conference on Power
Electronics and Drive Systems, vol. 2, pp. 530-534, 1997.
[21] 蘇長成，“風力發電系統之功率轉換器研製”，國立台灣科技大
學電機研究所碩士論文，民國九十七年。
[22] 謝辰勻，“具轉速發電機之轉速及位置偵測裝置的永磁式同步電
動機驅動系統研製”，國立台灣科技大學電機研究所碩士論文，
民國九十七年。
[23] 魏孝哲，“六臂型三相變流器之永磁式同步電動機驅動器之故障
後控制策略”，國立台灣科技大學電機研究所碩士論文，民國九
十八年。
[24] 陳俊男，“永磁式同步電動機驅動器之參數量測及故障前診
斷”，國立台灣科技大學電機研究所碩士論文，民國九十七年。
[25] 劉建村，“六相永磁式同步電動機設計及故障後控制策略”，國
立台灣科技大學電機研究所碩士論文，民國九十九年。
[26] 許溢适，“實用電動機設計手冊”，電機控制與電力電子譯著叢
書30，民國九十六年。