Sensorless control of salient PMSM drives in the transition region
Journal article, 2006

This paper considers speed and position estimation of salient permanent-magnet synchronousmachines (PMSMs). An estimator of phase-locked loop (PLL) type is considered. Signal injection techniques are used in the zero-speed and low-speed regions, while information found in the back electromotive force (EMF) is used for higher speeds. Particular focus is put on the transition region, i.e., the speed region where the estimator switches between signal-injection and back-EMF-based methods. It is shown that the estimator may become unstable for certain setups of machine parameters and operating conditions if the transition region is determined incorrectly. To avoid this instability, design rules for how the transition region should be determined, as well as recommended selections for all parameters introduced, are given. The results of the analysis are also supported with experimental results.

phase-locked loop

Permanent magnet synchronous machine

speed estimation

signal injection

position estimation

sensorless control


Oskar Wallmark

Chalmers, Energy and Environment, Electric Power Engineering

Lennart Harnefors


IEEE Transactions on Industrial Electronics

0278-0046 (ISSN)

Vol. 53 4 1179-1187

Subject Categories

Other Electrical Engineering, Electronic Engineering, Information Engineering



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