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Using the AC Drive Motor as a Transducer for Detecting Electrical and Electromechanical Faults

By Mark Lane

Abstract

Condition monitoring of AC motors is a subject area that has received extensive research. Whether this monitoring is carried out on a scheduled basis by engineer intervention, or continuously using an on-line unit, the results of this testing enable preventative maintenance work to be a carried out earlier, before any major failure occurs. Monitoring using vibration analysis is the most common and depending on the plant, can be done once or twice a year. This is usually limited to the condition of motor bearings and is not commonly used to detect failures in the motor electromagnetic systems. Monitoring units that use motor current measurements are also available, but these are less widely-used and usually on major plant motors (>250kW for example) that have a large capital outlay to replace. \ud \ud \ud The industry drivers – as always – are maximum plant and machinery uptime, with the minimal amount of scheduled maintenance. If maintenance is carried out too regularly, costs rise significantly not only due to the maintenance activity itself, but disruption to production schedules. Maintenance schedules that are too infrequent can result in an unacceptable rise in total failures of plant that are unexpected and may cause a significant amount of production disruption and downtime, especially if this occurs during out-of-hours working time. However, industry now faces another big challenge and one that has had a good share of exposure over the last few years. It is of course, the drive to reduce carbon emissions and with it the amount of energy that a plant itself consumes. What has brought this more to the fore recently is the significant rise in energy costs. Whilst product margins have to remain the same, many companies energy costs have seen a two to three-fold increase in energy budgets in the last few years alone. For industry processes that have a significant amount of fan and pump applications, the manufacturers of low-cost AC inverters have saturated the lower-performance market of inverter drives such that any drive can control these type of fan and pump applications, where accurate speed control is not a major driver.\ud \ud \ud Unfortunately, this can be a step backwards for end-users of plant that use equipment to monitor motor condition via motor current signals. Additionally, vibration analysis that relies upon ‘base-lining’ motor data when the AC motor is running at base speed may not give accurate readings when the motor is under inverter control and running at a different speed. \ud \ud \ud For manufacturers of AC inverter drives in this low-end market, it can be difficult to sell a product from one manufacturer over another without the unit having a “USP”, or Unique Selling Proposition. Most decisions taken on inverter equipment purchase at this level are usually in favour of the equipment that costs the least to purchase. Credibility of manufacturers based on product history and perceived reliability cuts little ground with an ever cost-conscious industry. \ud \ud \ud This is where the research into diagnosis of faults on inverter driven motor systems can provide just this USP for manufacturers. If the incorporation of on-line diagnosis for simple inverter applications can be brought to a typical inverter unit at a reasonable cost, the manufacturer who can offer this gains a unique foothold in the marketplace – a drive that can monitor and signal that the motor it is driving is showing signs of early failure. \ud \ud \ud It will be sensible to limit this research to simple inverter applications as high-end inverter drives that operate equipment such as high-speed printing presses, rotary shears will be more difficult to model and simulate than a fan or pump application.\ud \ud \ud It is hoped that a typical inverter drive can relay enough detailed information about the load which it is driving to allow this to be used for abnormal motor load conditions as this will provide a platform on which to extend the research beyond this MSc and into the realms of incorporating such technology into a drive manufacturers equipment. If this can be done without major modification to an inverter, then it may be easier to implement in equipment offered by different manufacturers. \ud \ud \ud It is quite possible that this technology could be licensed under a name that guarantees the performance of the condition monitoring algorithms and reliability from one drive manufacturer to another

Topics: TA, TK
OAI identifier: oai:eprints.hud.ac.uk:10167

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Citations

  1. A Wavelet Tour of Signal doi
  2. A Wavelet Tour of Signal Processing,” doi
  3. (1998). AI techniques in induction machines diagnosis including the speed ripple effect”, doi
  4. Bank; 50kW, 250VDC; Drawing number: FE 081073 Issue B; Electrohm Limited Ohms House, Woodlands Business Park,
  5. Bogusław Łazarz2, Henryk Madej3, Grzegorz Wojnar4; “Classification of tooth gear wheel faults of gearbox working in the circulating power test rig by multilayer perceptron and continuous wavelet transform”; 1-4Faculty
  6. (1995). Carla Tassoni2; “Neural Networks Aided On-Line Diagnostics of Induction Motor Rotor Faults”;
  7. Carla Tassoni2; “Recent Developments of Induction Motor Drives Fault Diagnosis Using
  8. (2001). Condition monitoring and Fault Diagnosis of Three-Phase Induction Motors”,
  9. (1986). Condition monitoring of electrical drives”. doi
  10. (1993). Condition Monitoring Of Inverter Fed Motors”;
  11. (1997). Control of Electrical Drives”, 2nd Completely Revised and Enlarged Edition, Technische Universität Braunschweig ,
  12. Current Harmonics Analysis of Inverter-Fed Induction Motor Drive System under Fault Conditions “;
  13. Doĝan Gökhan Ece, Ömer Nezih Gerek, “Induction machine condition monitoring using notch-filtered motor current.” doi
  14. Drives HTTL Speed Feedback Communications Option Technical Manual for 690+ Frame C+
  15. (1986). et al “Assessment of the reliability of motors in utility applications – Part 1”,
  16. (1987). et al “Assessment of the reliability of motors in utility applications – Part 2”,
  17. European Electric Motors; Written by Dr David G Searle; A Drives and Controls Publication, published on behalf of Eurotherm Drives Ltd.
  18. Fault Detection of 3-Phase VSI using Wavelet-Fuzzy Algorithm“; doi
  19. Fault Diagnostics in an Inverter Feeding an Induction Motor”; Mohamed Electronics Research Institute - Dokki,
  20. (2009). Gearbox Fault Diagnosis based on Vibration Signals Measured Remotely”; doi
  21. Helical geared motor view taken from: http://www.radicon.com/geared-motor-seriesm.php Radicon Website (formerly
  22. (2010). Images taken from: http://www.automation.siemens.com/bilddb/index.aspx?lang=en Siemens Automation and Drives Image Database Website Portal; Last used 03rd
  23. Incipient Fault Diagnosis in Electrical Drives by Tuned Neural Networks”; doi
  24. Induction Motors’ Faults Detection and Localization Using Stator Current Advanced Signal Processing Techniques; doi
  25. (2004). Instantaneous angular speed monitoring of electric motors”. doi
  26. Investigation of Fault Modes of Voltage-Fed Inverter System for Induction Motor Drive”; doi
  27. Károly Ágoston BIRÓ1, Dénes FODOR2, Ernő KOVÁCS3; “Improved Condition Monitoring System for Induction Machines Using a Model-Based Fault Detection Approach”;
  28. (2010). Kwan Chiman; “Wireless health monitoring system for vibration detection of induction motors.” doi
  29. (2004). Monitoring gear vibrations through motor current signature analysis and wavelet transform. doi
  30. Motor Current Signature Analysis To Detect Faults In Induction Motor Drives—Fundamentals, Data Interpretation, And Industrial Case Histories”; doi
  31. (2009). Operating Instructions Siemens Simovert Masterdrives Frequency Converter (AC-AC)
  32. Radicon Series M Helical In
  33. (1985). Report of large motor reliability survey of industrial and commercial installations – Part 1”, doi
  34. (1985). Report of large motor reliability survey of industrial and commercial installations – Part 2”, doi
  35. (1987). Report of large motor reliability survey of industrial and commercial installations – Part 3”, doi
  36. Senior Member, IEEE; “Intelligent Diagnosis of Open and Short Circuit Faults in Electric Drive Inverters For Real-Time Applications”; doi
  37. Siemens Operating Instructions 10/2008 English for IEC Low-voltage Motors; Siemens AG Industry Sector,
  38. (2010). Six-step Inverter Block Diagram; http://www.mathworks.com/access/helpdesk/help/toolbox/physmod/powersys/ref/sixst epvsiinductionmotordrive.html; Last Used:
  39. (2010). Source File:3-fas-spänningar.svg; “Author:
  40. (1992). Ten Lectures on Wavelet,” Society for Industrial and Applied Mathematics,
  41. (2009). The Use of Parameter Identification Methods for the Condition Monitoring of Electric Motor Drives”,
  42. (1996). Vector control and Dynamic of AC Drives”,
  43. (2009). Y.Shao b, N.Huc, A.Naid a, A.D.Ball a. (7 doi

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