A general magnetic-energy-based torque estimator: validation via a permanent-magnet motor drive

Cossar, C., Popescu, M., Miller, T.J.E., McGilp, M.I. and Olaru, M. (2008) A general magnetic-energy-based torque estimator: validation via a permanent-magnet motor drive. IEEE Transactions on Industry Applications, 44(4), pp. 1210-1217. (doi: 10.1109/TIA.2008.926231)

Abstract

This paper describes the use of the current–flux-linkage ($i{-}psi$ ) diagram to validate the performance of a general magnetic-energy-based torque estimator. An early step in the torque estimation is the use of controller duty cycles to reconstruct the average phase-voltage waveform during each pulsewidth-modulation (PWM) switching period. Samples over the fundamental period are recorded for the estimation of the average torque. The fundamental period may not be an exact multiple of the sample time. For low speed, the reconstructed voltage requires additional compensation for inverter-device losses. Experimental validation of this reconstructed waveform with the actual PWM phase-voltage waveform is impossible due to the fact that one is PWM in nature and the other is the average value during the PWM period. A solution to this is to determine the phase flux-linkage using each waveform and then plot the resultant $i{-}psi$ loops. The torque estimation is based on instantaneous measurements and can therefore be applied to any electrical machine. This paper includes test results for a three-phase interior permanent-magnet brushless ac motor operating with both sinusoidal and nonsinusoidal current waveforms.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Miller, Prof Timothy
• Authors: Cossar, C., Popescu, M., Miller, T.J.E., McGilp, M.I., and Olaru, M.
• Subjects: T Technology > TK Electrical engineering. Electronics Nuclear engineering
• College/School: College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
• Journal Name: IEEE Transactions on Industry Applications
• Publisher: Institute of Electrical and Electronics Engineers
• ISSN: 0093-9994
• Copyright Holders: Copyright © 2008 Institute of Electrical and Electronics Engineers
• First Published: First published in IEEE Transactions on Industry Applications 44(4):1210-1217
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher