TY - JOUR

T1 - Optimal number of stator poles for compact active radial magnetic bearings

AU - Matsuda, Koichi

AU - Kanemitsu, Yoichi

AU - Kijimoto, Shinya

PY - 2007/8/1

Y1 - 2007/8/1

N2 - We present a method for finding the optimal number of stator poles for active radial magnetic bearings that minimizes the stator outside diameter. We use magnetic circuit analysis to determine the number of turns of wire to generate the worst case load capacity within limits of coil currents and flux densities. Using the analysis, we developed six types of magnetic bearing for a given value of journal diameter. We found that 3-pole bearings yield the smallest outside diameter among the six types of bearing for a journal diameter less than 50 mm; however, all the bearings have almost the same outside diameter for a journal diameter larger than 200 mm. For an infinite-length bearing, the stator diameter is a linear function of the product of numbers of poles and coil turns. We applied a linear controller design method to a heteropolar 3-pole magnetic bearing that has nonlinear coupling between the orthogonal components of bearing force. With this controller, we successfully levitated a slender-rotor system and rotated it at 3571 rpm.

AB - We present a method for finding the optimal number of stator poles for active radial magnetic bearings that minimizes the stator outside diameter. We use magnetic circuit analysis to determine the number of turns of wire to generate the worst case load capacity within limits of coil currents and flux densities. Using the analysis, we developed six types of magnetic bearing for a given value of journal diameter. We found that 3-pole bearings yield the smallest outside diameter among the six types of bearing for a journal diameter less than 50 mm; however, all the bearings have almost the same outside diameter for a journal diameter larger than 200 mm. For an infinite-length bearing, the stator diameter is a linear function of the product of numbers of poles and coil turns. We applied a linear controller design method to a heteropolar 3-pole magnetic bearing that has nonlinear coupling between the orthogonal components of bearing force. With this controller, we successfully levitated a slender-rotor system and rotated it at 3571 rpm.

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U2 - 10.1109/TMAG.2007.900184

DO - 10.1109/TMAG.2007.900184

M3 - Article

AN - SCOPUS:34547409801

VL - 43

SP - 3420

EP - 3427

JO - IEEE Transactions on Magnetics

JF - IEEE Transactions on Magnetics

SN - 0018-9464

IS - 8

ER -