Shaft torsion deformation and unit combination on torque ripple of permanent magnet motor for direct driven submersible screw pump
ZHANG Bing yi, XV Zhi ping, FENG Gui hong
（School of Electrical Engineering, Shenyang University of Technology, Shenyang 110870, China）

Abstract: Aiming at the torque ripple problem of direct driven submersible screw pump permanent magnet motor brought by its slender shaft torsion deformation when the motor operated with load and unit combination structure, the shaft torsion deformation angle was accurately calculated by finite element simulation, the relationship between torsion deformation angle and torque ripple was analyzed in detail and proved, the influence on torque ripple brought by unit combination structure was studied, method which can reduce the influence was found and proved by prototype experiment. The results indicate that the torque ripple brought by shaft torsion deformation isn t obvious; the unit combination has a great influence on the torque ripple of the submersible motor, changing the relative position of adjacent unit motor stator can reduce this influence effectively which can provide some suggestions about reducing the torque ripple of unit combination motor.

Key words: shaft torsion deformation; unit combination; torque ripple; simulation; prototype experiment