Title :
Magnetic lumped parameter modeling of rotor eccentricity in brushless permanent-magnet motors
Author :
Wang, Jim-Po ; Lieu, Dennis K.
Author_Institution :
Dept. of Mech. Eng., California Univ., Berkeley, CA, USA
fDate :
9/1/1999 12:00:00 AM
Abstract :
Vibration, giving rise to acoustical noise, is an important index of motor performance. The unbalanced force due to rotor eccentricity caused by manufacturing imprecision or bearing defects is one possible source of excitation to vibration. The previously developed fast design package for permanent magnet motors, based on magnetic lumped parameter modeling, is modified to predict the influence of rotor eccentricity. Both static and dynamic cases are investigated. Magnetic material nonlinearity is taken into consideration. A two-dimensional relative permeance function is derived by conformal transformation followed by the modification of permeances modeling the air gap. Static and dynamic rotor eccentricity bring different effects to symmetric and asymmetric motors and are discussed separately
Keywords :
brushless machines; machine theory; permanent magnet motors; rotors; acoustic noise; air gap; brushless permanent magnet motor; conformal transformation; design; magnetic lumped parameter model; magnetic material nonlinearity; rotor eccentricity; two-dimensional relative permeance function; unbalanced force; vibration; Magnetic analysis; Magnetic flux; Magnetic levitation; Magnetic materials; Magnetic separation; Manufacturing; Permanent magnet motors; Rotors; Saturation magnetization; Vibrations;
Journal_Title :
Magnetics, IEEE Transactions on