On Radio-Frequency-Based Detection of High-Frequency Circulating Bearing Current Flow

The possibility of bearing damage caused by inverter-induced bearing currents in modern variable-speed drive systems has been well recognized today. Further research is needed to develop appropriate nonintrusive methods for detection and monitoring of such currents. A radio-frequency-based nondestructive method has been applied to detect discharge bearing currents. The method is understood to work on the energy that is radiated in the electric field during the bearing discharge event. We show that the method is also applicable to high-frequency circulating bearing currents that have so far been associated with ohmic bearing characteristics and no discharges occurring. The analysis and understanding of the applicability of the method to detect such currents also contributes to further understanding of the electric characteristics of the bearing, notably the moment the current conduction begins.

[1]  D. Hyypio,et al.  Mitigation of bearing electro-erosion of inverter-fed motors through passive common-mode voltage suppression , 2003, IEEE Transactions on Industry Applications.

[2]  A. Muetze,et al.  Techniques for Measurement of Parameters Related to Inverter-Induced Bearing Currents , 2007, IEEE Transactions on Industry Applications.

[3]  Annette Muetze,et al.  Calculation of Circulating Bearing Currents in Machines of Inverter-Based Drive Systems , 2004, IEEE Transactions on Industrial Electronics.

[4]  A Cavallini,et al.  Monitoring off-line and on-line PD under impulsive voltage on induction motors - part 1: standard procedure , 2010, IEEE Electrical Insulation Magazine.

[5]  H. Akagi,et al.  An approach to eliminating high-frequency shaft voltage and leakage current from an inverter-driven motor , 2003, 38th IAS Annual Meeting on Conference Record of the Industry Applications Conference, 2003..

[6]  Jussi Tamminen,et al.  Radio-frequency-based detection of electrical discharge machining bearing currents , 2011 .

[7]  M. V. Cistelecan,et al.  Evaluation of Slot-Embedded Partial Electrostatic Shield for High-Frequency Bearing Current Mitigation in Inverter-Fed Induction Motors , 2012, IEEE Transactions on Energy Conversion.

[8]  Doyle F. Busse,et al.  Bearing currents and their relationship to PWM drives , 1997 .

[9]  Thomas A. Lipo,et al.  Modeling of motor bearing currents in PWM inverter drives , 1995 .

[10]  A. Cavallini,et al.  Monitoring off-line and on-line PD under impulsive voltage on induction motors - Part 3: Criticality , 2011, IEEE Electrical Insulation Magazine.

[11]  G. Stone,et al.  Partial-discharge-inception testing on low-voltage motors , 2004, IEEE Transactions on Industry Applications.

[12]  A. Binder,et al.  Experimental evaluation of mitigation techniques for bearing currents in inverter-supplied drive-systems - investigations on induction motors up to 500 kW , 2003, IEEE International Electric Machines and Drives Conference, 2003. IEMDC'03..

[13]  J. Erdman,et al.  Effect of PWM inverters on AC motor bearing currents and shaft voltages , 1995, Proceedings of 1995 IEEE Applied Power Electronics Conference and Exposition - APEC'95.

[14]  R.J. Kerkman,et al.  Gear up your bearings , 2008, IEEE Industry Applications Magazine.

[15]  Jero Ahola,et al.  On the Role of the Shaft End and the Influence of Frame Size and Load Coupling on the RF Emission Characteristics of Induction Motors , 2013 .

[16]  A. Muetze,et al.  Influence of Motor Operating Parameters on Discharge Bearing Current Activity , 2010, IEEE Transactions on Industry Applications.

[17]  Thomas A. Lipo,et al.  Source of induction motor bearing currents caused by PWM inverters , 1996 .

[18]  A Cavallini,et al.  Off-line PD testing of converter-fed wire-wound motors: when IEC TS 60034-18-41 may fail? , 2010, IEEE Transactions on Dielectrics and Electrical Insulation.

[19]  H. E. Boyanton,et al.  Bearing fluting [motors] , 2002 .

[20]  A Cavallini,et al.  Monitoring off-line and on-line PD under impulsive voltage on induction motors - Part 2: testing* , 2011, IEEE Electrical Insulation Magazine.

[21]  H.W. Oh,et al.  Design Aspects of Conductive Microfiber Rings for Shaft Grounding Purposes , 2007, 2007 IEEE Industry Applications Annual Meeting.

[22]  A. Muetze,et al.  Don’t lose your bearings – Mitigation techniques for bearing currents in inverter-supplied drive systems , 2006 .

[23]  G.C. Stone,et al.  Electrical insulation for rotating machines-design, evaluation, aging, testing, and repair - Book Review , 2004, IEEE Electrical Insulation Magazine.

[24]  P. J. Link,et al.  Minimizing electric bearing currents in ASD systems , 1999 .

[25]  Annette Muetze,et al.  Practical Rules for Assessment of Inverter-Induced Bearing Currents in Inverter-Fed AC Motors up to 500 kW , 2007, IEEE Transactions on Industrial Electronics.

[26]  Doyle F. Busse,et al.  An evaluation of the electrostatic shielded induction motor: a solution for rotor shaft voltage buildup and bearing current , 1996, IAS '96. Conference Record of the 1996 IEEE Industry Applications Conference Thirty-First IAS Annual Meeting.

[27]  M.J. Melfi,et al.  Bearing current remediation options , 2004, IEEE Industry Applications Magazine.

[28]  Annette Muetze,et al.  Study on Bearing Impedance Properties at Several Hundred Kilohertz for Different Electric Machine Operating Parameters , 2013, IEEE Transactions on Industry Applications.

[29]  Shigeo Morimoto,et al.  Suppressing Bearing Voltage in an Inverter-Fed Ungrounded Brushless DC Motor , 2013, IEEE Transactions on Industrial Electronics.