Abstract
In modern rail transportation, inverter drive systems have been extensively used due to their excellent speed control capabilities. However, in recent years, premature failure problems caused by bearing voltage and current phenomena have been frequently reported in electric motors, with electrical bearing failures making up a considerable percentage. The purpose of this review is to provide a comprehensive overview of facets relating to the electrical erosion of bearings in an electrical environment represented by railway vehicles. First, the origins of the phenomenon as well as typical bearing electrical failure modes are discussed. Next, we introduce the distinctive features of the electrical environment of railway traction motor bearings, including output voltages with high common-mode components and systems with complex grounding configurations. Then, we classify the fundamental mechanisms for generating bearing voltages/currents into four groups, and present their modeling processes, including equivalent circuit establishment and parameter determination methods. Furthermore, we summarize the strategies frequently used to protect bearings, and describe a typical solution to suppress electrical bearing failures in railway vehicles. Finally, we present a case example to illustrate a research procedure for systematic investigation of inverter-induced bearing currents in rail transportation.
概要
目的
脉冲宽度调制（PWM）变频驱动使轨道交通牵引电机获得了良好的运行性能,但由于输出电压存在共模分量,导致了轴承电压和轴承电流的产生,进而引起轴承早期失效。本文旨在回顾轴承电压根源、轴承电蚀失效模式、轴承电流形成机理、轴承电流共模等效电路、耦合回路阻抗提取和抑制对策等方面的研究现状,并重点围绕轨道交通牵引系统电机及负载接地状况对轴承电压的影响展开全面研究。
创新点
1. 总结PWM变频系统轴承电流分析与建模方法和抑制对策与效果;2. 分析轨道交通牵引系统电机接地配置对轴承电压的影响,并通过共模等效电路模型成功模拟了不同转速下的轴承电压波形,验证了采用接地环和调整系统接地阻抗可以降低轴承电压。
方法
1. 通过文献搜索和调研,总结PWM变频系统轴承电流的研究方法和思路;2. 结合实际轨道交通牵引电机系统接地状况,得到共模等效电路模型和提取回路阻抗参数,并通过仿真模拟与实际测量轴承电压波形,验证模型的**确性;3. 通过实际测量,验证接地环和调整系统接地阻抗是否可以降低轴承电压。
结论
1. 轨道交通牵引系统电机轴承电压与定转子接地阻抗有关,可产生转轴接地型轴承电流;2. 通过转轴侧接地共模等效电路,可以模拟不同转速下的轴承电压波形;3. 通过适当调整系统保护接地回路,降低电机定子侧接地阻抗,可以实现降低轴承电压的目标。
This is a preview of subscription content, log in via an institution to check access.
References
ABB, 2021. Rogowski Coil Current Sensors for Arc Flash Detection. ABB Review. https://new.abb.com/news/detail/78554/rogo-wski-coil-current-sensors-for-arc-flash-detection
Adabi J, Zare F, Ghosh A, et al., 2010. Calculations of capacitive couplings in induction generators to analyse shaft voltage. IET Power Electronics, 3(3):379–390. https://doi.org/10.1049/iet-pel.2008.0332
AEGIS, 2007. Shaft Grounding Rings for Low Voltage Motors. https://www.est-aegis.com/product/sgr/
AEGIS, 2018. Bearing Protection Handbook: Best Practices for Bearing Protection in New and Repaired Motors, Testing In-Service Motors, and Inspecting Damaged Motor Bearings. https://www.morganadvancedmaterials.com/media/7645/aegis-bearing-protection.pdf
Akagi H, Tamura S, 2006. A passive EMI filter for eliminating both bearing current and ground leakage current from an inverter-driven motor. IEEE Transactions on Power Electronics, 21(5):1459–1469. https://doi.org/10.1109/TPEL.2006.880239
Alger PL, Samson HW, 1924. Shaft currents in electric machines. Transactions of the American Institute of Electrical Engineers, XLIII:235–245. https://doi.org/10.1109/T-AIEE.1924.5060981
Ammann C, Reichert K, Joho R, et al., 1988. Shaft voltages in generators with static excitation systems-problems and solution. IEEE Transactions on Energy Conversion, 3(2): 409–419. https://doi.org/10.1109/60.4749
Bai BD, Wang Y, Wang XC, 2015. Suppression for discharging bearing current in variable-frequency motors based on electromagnetic shielding slot wedge. IEEE Transactions on Magnetics, 51(11):8109404. https://doi.org/10.1109/TMAG.2015.2439961
Berhausen S, Jarek T, 2022. Analysis of impact of design solutions of an electric machine with permanent magnets for bearing voltages with inverter power supply. Energies, 15(12):4475. https://doi.org/10.3390/en15124475
Bhattacharya S, Resta L, Divan DM, et al., 1999. Experimental comparison of motor bearing currents with PWM hard- and soft-switched voltage-source inverters. IEEE Transactions on Power Electronics, 14(3):552–562. https://doi.org/10.1109/63.761699
Bonnett AH, Yung C, 2006. A construction, performance and reliability comparison for pre-EPAct, EPAct and premium-efficient motors. Record of Conference Papers-IEEE Industry Applications Society 53rd Annual Petroleum and Chemical Industry Conference. https://doi.org/10.1109/PCICON.2006.359691
Boyanton HE, Hodges G, 2002. Bearing fluting [motors]. IEEE Industry Applications Magazine, 8(5):53–57. https://doi.org/10.1109/MIA.2002.1028391
Boyd J, Kaufman HN, 1958. The causes and control of electrical currents in bearings. Lubrication Engineering, 2(6): 28–35.
Buckley GW, Corkins RJ, Stephens RN, 1988. The importance of grounding brushes to the safe operation of large turbine generators. IEEE Transactions on Energy Conversion, 3(3):607–612. https://doi.org/10.1109/60.8075
Busse DF, Erdman JM, Kerkman RJ, et al., 1997a. Bearing currents and their relationship to PWM drives. IEEE Transactions on Power Electronics, 12(2):243–252. https://doi.org/10.1109/63.558735
Busse DF, Erdman JM, Kerkman RJ, et al., 1997b. Characteristics of shaft voltage and bearing currents. IEEE Industry Applications Magazine, 3(6):21–32. https://doi.org/10.1109/2943.628116
Busse DF, Erdman JM, Kerkman RJ, et al., 1997c. The effects of PWM voltage source inverters on the mechanical performance of rolling bearings. IEEE Transactions on Industry Applications, 33(2):567–576. https://doi.org/10.1109/28.568024
Busse DF, Erdman JM, Kerkman RJ, et al., 1997d. System electrical parameters and their effects on bearing currents. IEEE Transactions on Industry Applications, 33(2):577–584. https://doi.org/10.1109/28.568025
Busse DF, Erdman JM, Kerkman RJ, et al., 1997e. An evaluation of the electrostatic shielded induction motor: a solution for rotor shaft voltage buildup and bearing current. IEEE Transactions on Industry Applications, 33(6):1563–1570. https://doi.org/10.1109/28.649969
Chen SM, Lipo TA, Fitzgerald D, 1996. Source of induction motor bearing currents caused by PWM inverters. IEEE Transactions on Energy Conversion, 11(1):25–32. https://doi.org/10.1109/60.486572
Chen ST, Lipo TA, 1998. Circulating type motor bearing current in inverter drives. IEEE Industry Applications Magazine, 4(1):32–38. https://doi.org/10.1109/2943.644884
Chen ST, Lipo TA, Fitzgerald D, 1996. Modeling of motor bearing currents in PWM inverter drives. IEEE Transactions on Industry Applications, 32(6): 1365–1370. https://doi.org/10.1109/28.556640
Chen ZW, 2021. Comparative Study of Grounding Reflux Schemes for Metro Vehicles. MS Thesis, Bei**g Jiaotong University, Bei**g, China (in Chinese).
Cheng ZL, Zhou WH, Ding Z, et al., 2020. Estimation of spatiotemporal response of rooted soil using a machine learning approach. Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 21(6):462–477. https://doi.org/10.1631/jzus.A1900555
Costello MJ, 1993. Shaft voltages and rotating machinery. IEEE Transactions on Industry Applications, 29(2):419–426. https://doi.org/10.1109/28.216553
Ferreira FJTE, Cistelecan MV, De Almeida AT, 2012. Evaluation of slot-embedded partial electrostatic shield for high-frequency bearing current mitigation in inverter-fed induction motors. IEEE Transactions on Energy Conversion, 27(2):382–390. https://doi.org/10.1109/TEC.2012.2187452
Fleishmann L, 1910. Currents in bearings and shafts. Elecktrische Kraftbetriebe and Bahnen, 11(8): 11–17 (in German).
Furtmann A, Tischmacher H, Poll G, 2016. Extended HF equivalent model of a drive train. XXII International Conference on Electrical Machines, p.2244–2250. https://doi.org/10.1109/ICELMACH.2016.7732834
Guttowski S, Weber S, Schinkel M, et al., 2006. Trouble-shooting and fixing of inverter driven induction motor bearing currents in existing plants of large size-an evaluation of possible mitigation techniques in practical applications. Twenty-First Annual IEEE Applied Power Electronics Conference and Exposition, p.6. https://doi.org/10.1109/APEC.2006.1620544
Han Y, Lu HF, Li YD, et al., 2019. Analysis and suppression of shaft voltage in SiC-based inverter for electric vehicle applications. IEEE Transactions on Power Electronics, 34(7):6276–6285. https://doi.org/10.1109/TPEL.2018.2873079
Hedayati MH, Acharya AB, John V, 2013. Common-mode filter design for PWM rectifier-based motor drives. IEEE Transactions on Power Electronics, 28(11):5364–5371. https://doi.org/10.1109/TPEL.2013.2238254
Holmes DG, Lipo TA, 2003. Pulse Width Modulation for Power Converters: Principles and Practice. John Wiley & Sons, Inc., Hoboken, USA.
Hyypio D, 2005. Mitigation of bearing electro-erosion of inverter-fed motors through passive common-mode voltage suppression. IEEE Transactions on Industry Applications, 41(2):576–583. https://doi.org/10.1109/TIA.2005.844373
IEC (International Electrotechnical Commission), 2014. Rotating Electrical Machines—Part 25: AC Electrical Machines Used in Power Drive Systems—Application Guide, IEC TS 60034-25. IEC.
IEEE (Institute of Electrical and Electronics Engineers), 1997. IEEE Standard Test Procedure for Polyphase Induction Motors and Generators, IEEE Standard 112-1996. IEEE.
Liu RF, Chen JY, Ma XP, et al., 2014a. Calculation and measurement of coupling capacitances in AC motors based on bearing currents problem induced by PWM inverters. Transactions of China Electrotechnical Society, 29(1): 60–67 (in Chinese). https://doi.org/10.19595/j.cnki.1000-6753.tces.2014.01.009
Liu RF, Lou ZF, Ma XP, et al., 2014b. Modeling of bearing capacitance and resistance in motor bearing current problem. Proceedings of the CSEE, 34(15):2430–2437 (in Chinese). https://doi.org/10.13334/j.0258-8013.pcsee.2014.15.013
Liu RF, Sang BQ, Cao JC, 2015a. Investigation on the influence of motors grounding states on bearing voltage in inverter drive system. Proceedings of the CSEE, 35(S1):177–183 (in Chinese). https://doi.org/10.13334/j.0258-8013.pcsee.2015.S.024
Liu RF, Li JF, Sang BQ, et al., 2015b. Modeling of coupled capacitances and bearing voltage in induction motors fed by inverters based on numerical calculation of electromagnetic field. Transactions of China Electrotechnical Society, 30(14):161–169 (in Chinese). https://doi.org/10.3969/j.issn.1000-6753.2015.14.022
Liu RF, Sang BQ, Li WL, 2017. Calculations and measurements of bearing capacitance in AC motor bearings. Proceedings of the CSEE, 37(10):2986–2993 (in Chinese). https://doi.org/10.13334/j.0258-8013.pcsee.160610
Luo ZX, 2021. Research on traction motor bearing electric erosion of metro vehicle and its improvement measures. Electric Drive for Locomotives, (2):37–41 (in Chinese). https://doi.org/10.13890/j.issn.1000-128x.2021.02.007
Magdun O, Binder A, 2009. Calculation of roller and ball bearing capacitances and prediction of EDM currents. The 35th Annual Conference of IEEE Industrial Electronics, p.1051–1056. https://doi.org/10.1109/IECON.2009.5414669
Magdun O, Binder A, 2014. High-frequency induction machine modeling for common mode current and bearing voltage calculation. IEEE Transactions on Industry Applications, 50(3):1780–1790. https://doi.org/10.1109/TIA.2013.2284301
Magdun O, Gemeinder Y, Binder A, 2010a. Investigation of influence of bearing load and bearing temperature on EDM bearing currents. IEEE Energy Conversion Congress and Exposition, p.2733–2738. https://doi.org/10.1109/ECCE.2010.5618061
Magdun O, Gemeinder Y, Binder A, 2010b. Prevention of harmful EDM currents in inverter-fed AC machines by use of electrostatic shields in the stator winding overhang. The 36th Annual Conference on IEEE Industrial Electronics Society, p.962–967. https://doi.org/10.1109/IECON.2010.5675498
Magdun O, Gemeinder Y, Binder A, et al., 2011. Calculation of bearing and common-mode voltages for the prediction of bearing failures caused by EDM currents. The 8th IEEE Symposium on Diagnostics for Electrical Machines, Power Electronics & Drives, p.462–467. https://doi.org/10.1109/DEMPED.2011.6063664
Muetze A, 2004. Bearing Currents in Inverter-Fed AC-Motors. PhD Thesis, Technische Universität Darmstadt, Darmstadt, Germany.
Muetze A, Binder A, 2006. Don’t lose your bearings. IEEE Industry Applications Magazine, 12(4):22–31. https://doi.org/10.1109/MIA.2006.1678327
Muetze A, Binder A, 2007a. Calculation of circulating bearing currents in machines of inverter-based drive systems. IEEE Transactions on Industrial Electronics, 54(2):932–938. https://doi.org/10.1109/TIE.2007.892001
Muetze A, Binder A, 2007b. Calculation of motor capacitances for prediction of the voltage across the bearings in machines of inverter-based drive systems. IEEE Transactions on Industry Applications, 43(3):665–672. https://doi.org/10.1109/TIA.2007.895734
Muetze A, Binder A, 2007c. Practical rules for assessment of inverter-induced bearing currents in inverter-fed AC motors up to 500 kW. IEEE Transactions on Industrial Electronics, 54(3):1614–1622. https://doi.org/10.1109/TIE.2007.894698
Muetze A, Binder A, 2007d. Techniques for measurement of parameters related to inverter-induced bearing currents. IEEE Transactions on Industry Applications, 43(5):1274–1283. https://doi.org/10.1109/TIA.2007.904413
Muetze A, Oh HW, 2008a. Application of static charge dissipation to mitigate electric discharge bearing currents. IEEE Transactions on Industry Applications, 44(1):135–143. https://doi.org/10.1109/TIA.2007.912758
Muetze A, Oh HW, 2008b. Design aspects of conductive microfiber rings for shaft-grounding purposes. IEEE Transactions on Industry Applications, 44(6):1749–1757. https://doi.org/10.1109/TIA.2008.2006421
Muetze A, Oh HW, 2010. Current-carrying characteristics of conductive microfiber electrical contact for high frequencies and current amplitudes: theory and applications. IEEE Transactions on Power Electronics, 25(8):2082–2092. https://doi.org/10.1109/TPEL.2010.2046499
Muetze A, Sullivan CR, 2011. Simplified design of common-mode chokes for reduction of motor ground currents in inverter drives. IEEE Transactions on Industry Applications, 47(6):2570–2577. https://doi.org/10.1109/TIA.2011.2170101
Plazenet T, Boileau T, 2021. Overview of bearing white etching cracks due to electrical currents. IEEE 13th International Symposium on Diagnostics for Electrical Machines, Power Electronics and Drives, p.440–446. https://doi.org/10.1109/SDEMPED51010.2021.9605561
Plazenet T, Boileau T, Caironi C, et al., 2018. A comprehensive study on shaft voltages and bearing currents in rotating machines. IEEE Transactions on Industry Applications, 54(4):3749–3759. https://doi.org/10.1109/TIA.2018.2818663
Punga F, Hess W, 1907. Bearing currents. Elektrotechnik und Maschinenbau, 25(8):615–618 (in German).
Raymond OKJ, 1999. An Investigation of Shaft Current in a Large Sleeve Bearing Induction Machine. PhD Thesis, McMaster University, Ontario, Canada.
Shamsirband S, Khansari NM, 2021. Micro-mechanical damage diagnosis methodologies based on machine learning and deep learning models. Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 22(8): 585–608. https://doi.org/10.1631/jzus.A2000408
SKF, 2014. Electrical Discharge Detector Pen. SKF. https://www.skf.com/group/products/condition-monitoring-systems/basic-condition-monitoring-products/electrical-discharge-current-measurement
SKF, 2019. SKF @ptitude Analyst. https://www.skf.com/binaries/pub12/Images/0901d1968059796b-PUB-CM-P8-10299-12-EN-SKF-Aptitude-Analyst-brochure_tcm_12-582180.pdf
SKF, 2022. The Future of Bearing Failure Analysis is Here. https://evolution.skf.com/en/the-future-of-bearing-failure-analysis-is-here/
Sunahara K, Ishida Y, Yamashita S, et al., 2011. Preliminary measurements of electrical micropitting in grease-lubricated point contacts. Tribology Transactions, 54(5):730–735. https://doi.org/10.1080/10402004.2011.597543
Suzumura J, 2016. Prevention of electrical pitting on rolling bearings by electrically conductive grease. Quarterly Report of RTRI, 57(1):42–47. https://doi.org/10.2219/rtriqr.57.1_42
Tischmacher H, Gattermann S, 2010. Bearing currents in converter operation. The XIX International Conference on Electrical Machines, p.1–8. https://doi.org/10.1109/ICELMACH.2010.5608126
Tischmacher H, Gattermann S, 2012a. Investigations on bearing currents in converter-fed electrical motors. The XXth International Conference on Electrical Machines, p.1764–1770. https://doi.org/10.1109/ICElMach.2012.6350120
Tischmacher H, Gattermann S, 2012b. Multiple signature analysis for the detection of bearing currents and the assessment of the resulting bearing wear. International Symposium on Power Electronics Power Electronics, Electrical Drives, Automation and Motion, p.1354–1359. https://doi.org/10.1109/SPEEDAM.2012.6264380
Tischmacher H, Tsoumas IP, Furtmann A, 2015. Extended probability model for discharge activities in the drive train of converter-fed electric motors. The 17th European Conference on Power Electronics and Applications, p. 1–10. https://doi.org/10.1109/EPE.2015.7309392
Un E, Hava AM, 2009. A near-state PWM method with reduced switching losses and reduced common-mode voltage for three-phase voltage source inverters. IEEE Transactions on Industry Applications, 45(2):782–793. https://doi.org/10.1109/TIA.2009.2013580
Vostrov K, Pyrhönen J, Lindh P, et al., 2021. Mitigation of inverter-induced noncirculating bearing currents by introducing grounded electrodes into stator slot openings. IEEE Transactions on Industrial Electronics, 68(12):11752–11760. https://doi.org/10.1109/TIE.2020.3045695
Wang F, 2000. Motor shaft voltages and bearing currents and their reduction in multilevel medium-voltage PWM voltage-source-inverter drive applications. IEEE Transactions on Industry Applications, 36(5):1336–1341. https://doi.org/10.1109/28.871282
Wang Y, Bai BD, Liu WF, et al., 2015. Hertz bearing current density calculation of variable frequency driven motors by frequency domain parasitic capacitance method. Transactions of China Electrotechnical Society, 30(2):189–195 (in Chinese). https://doi.org/10.19595/j.cnki.1000-6753.tces.2015.02.025
Yan GL, Zhi YJ, Chen X, et al., 2019. Research on mechanism and suppression technique of metro vehicles traction motor bearing electrocorrosion. Electric Drive for Locomotives, (4):102–106 (in Chinese). https://doi.org/10.13890/j.issn.1000-128x.2019.04.113
Yea M, Han KJ, 2020. Modified slot opening for reducing shaft-to-frame voltage of AC motors. Energies, 13(3):760. https://doi.org/10.3390/en13030760
Zhang DM, Zhang JZ, Huang HW, et al., 2020. Machine learning-based prediction of soil compression modulus with application of 1D settlement. Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 21(6):430–444. https://doi.org/10.1631/jzus.A1900515
Zhang HR, von Jouanne A, Dai SA, et al., 2000. Multilevel inverter modulation schemes to eliminate common-mode voltages. IEEE Transactions on Industry Applications, 36(6):1645–1653. https://doi.org/10.1109/28.887217
Zhang PJ, Du Y, Habetler TG, et al., 2011. A survey of condition monitoring and protection methods for medium-voltage induction motors. IEEE Transactions on Industry Applications, 47(1):34–46. https://doi.org/10.1109/TIA.2010.2090839
Zhang SG, 2008. CRH1 EMU. China Railway Publishing House, Bei**g, China, p.134–166 (in Chinese).
Zhao QC, Yang EL, Liu RF, et al., 2021. Modeling of high frequency bearing currents of induction motors powered by frequency converters. Proceedings of the CSEE, 41(23): 8139–8147 (in Chinese). https://doi.org/10.13334/j.0258-8013.pcsee.210810
Zhao SF, Huang XY, Fang YT, et al., 2020. DC-link-fluctuation-resistant predictive torque control for railway traction permanent magnet synchronous motor in the six-step operation. IEEE Transactions on Power Electronics, 35(10): 10982–10993. https://doi.org/10.1109/TPEL.2020.2975497
Zhou LM, Huai XJ, Shen Z, et al., 2022. Common mode equivalent circuit modeling and parameter testing of traction motor. Electric Locomotives & Mass Transit Vehicles, 45(1):30–34. https://doi.org/10.16212/j.cnki.1672-1187.2022.01.007
Acknowledgments
This work is supported by the National Key R&D Program of China (No. 2018YFB1201804) and the National Natural Science Foundation of China (Nos. 52293424, 51827810, and 51977192).
Author information
Authors and Affiliations
Corresponding author
Additional information
Author contributions
Yao LI conducted the literature survey and wrote the first draft of the manuscript. Yongjian ZHI, Zifan GAO, Jien MA, and Jian ZHANG assisted with the literature survey and processed the experimental data. Lin QIU and Youtong FANG put forward the original idea of the proposed framework and supervised the research activities.
Conflict of interest
Yao LI, Lin QIU, Yongjian ZHI, Zifan GAO, Jien MA, Jian ZHANG, and Youtong FANG declare that they have no conflict of interest.
Rights and permissions
About this article
Cite this article
Li, Y., Qiu, L., Zhi, Y. et al. An overview of bearing voltages and currents in rail transportation traction motors. J. Zhejiang Univ. Sci. A 24, 226–242 (2023). https://doi.org/10.1631/jzus.A2200180
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1631/jzus.A2200180
Key words
- Rail transportation
- Bearing current
- Common-mode voltage
- Bearing electrical erosion
- Grounding configuration