Low-frequency signal-injection method for speed sensorless vector control of induction motors

No Thumbnail Available

URL

Journal Title

Journal ISSN

Volume Title

Doctoral thesis (article-based)
Checking the digitized thesis and permission for publishing
Instructions for the author

Date

2003-12-17

Major/Subject

Mcode

Degree programme

Language

en

Pages

70, [78]

Series

Institute of Intelligent Power Electronics publications, 7

Abstract

A new method for the speed sensorless vector control of induction motors at low speeds is presented. The method overcomes the well-known low-speed limitations of conventional methods based on an ideal motor model, yet without relying on a more detailed motor model or parasitic effects. To overcome the low-speed limitations, the ideal motor model is augmented with mechanical dynamics. The response of the electromechanical system to a low-frequency ac current signal injected into the stator winding depends on the direction of the signal relative to the rotor flux direction. Based on this dependency, a new algorithm for rotor flux angle estimation, applicable when the total moment of inertia is not too high, is developed. The estimation method tolerates any low-speed operation point, including zero stator frequency, which is validated by simulations and experiments. The robustness of the method against errors in motor parameter estimates is shown both theoretically and experimentally. The algorithm is also combined with a full-order flux observer, yielding fast dynamics in addition to steady-state stability at low speeds.

Description

Keywords

induction motor, sensorless control, rotor flux angle estimation, full-order flux observer

Other note

Parts

  • Leppänen V.-M. and Luomi J., 2001. Estimating the back-EMF of an induction motor. Proceedings of the 9th European Conference on Power Electronics and Applications (EPE 2001). Graz, Austria, 27-29 August 2001, on CD-ROM.
  • Leppänen V.-M. and Luomi J., 2002. Effect of equation of motion on low-frequency impedance of induction motors – an approach for rotor flux angle estimation. Proceedings of the 10th Power Electronics and Motion Control Conference (EPE-PEMC 2002). Cavtat & Dubrovnik, Croatia, 9-11 September 2002, on CD-ROM.
  • Leppänen V.-M. and Luomi J., 2002. A tracking controller for a speed sensorless induction machine drive. Proceedings of the 2002 Nordic Workshop on Power and Industrial Electronics (NORPIE 2002). Stockholm, Sweden, 12-14 August 2002, on CD-ROM.
  • Leppänen V.-M. and Luomi J., 2002. Rotor flux angle tracking controller for sensorless induction motor drives. Conference Record of the 2002 IEEE Industry Applications Conference (IAS 2002). Pittsburgh, PA, USA, 13-18 October 2002, Vol. 2, pages 856-863.
  • Leppänen V.-M. and Luomi J., 2002. Speed sensorless induction machine control for zero speed and frequency. Conference Record of the 28th Annual Conference of the IEEE Industrial Electronics Society (IECON'02). Sevilla, Spain, 5-8 November 2002, pages 400-405.
  • Leppänen V.-M. and Luomi J., 2003. Observer using low-frequency injection for sensorless induction motor control – parameter sensitivity analysis. Conference Record of the IEEE International Electric Machines and Drives Conference (IEMDC 2003). Madison, WI, USA, 1-4 June 2003, pages 609-616.
  • Leppänen V.-M., 2003. Low-frequency injection-based speed sensorless control of induction motors – applicability and implementation aspects. Proceedings of the 10th European Conference on Power Electronics and Applications (EPE 2003). Toulouse, France, 2-4 September 2003, on CD-ROM.
  • Hinkkanen M., Leppänen V.-M. and Luomi J., 2003. Flux observer enhanced with low-frequency signal injection allowing sensorless zero-frequency operation of induction motors. Conference Record of the 2003 IEEE Industry Applications Conference (IAS 2003). Salt Lake City, UT, USA, 12-16 October 2003, pages 1150-1156.
  • Kereszty T., Leppänen V.-M. and Luomi J., 2003. Sensorless control of surface magnet synchronous motors at low speeds using low-frequency signal injection. Conference Record of the 29th Annual Conference of the IEEE Industrial Electronics Society (IECON'03). Roanoke, VA, USA, 2-6 November 2003, pages 1239-1243.

Citation

Permanent link to this item

https://urn.fi/urn:nbn:fi:tkk-001154