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The influence of the magnetomotive force of the armature rea

Author:qiwo motor Views:Close

2021-03-24 10:31

 The influence of the armature reaction makes the zero-crossing point of the synthetic air-gap magnetic field lead the zero-crossing point of the original permanent magnetic field by an angle, and the size of this lead angle increases with the increase of the load current. The armature reacts to the magnetomotive force to move the best commutation point forward. The zero-crossing point of the synthetic air gap magnetic flux density is moved forward. In this way, the commutation position determined by the symmetrical magnetic field at no load is no longer suitable for load operation. If the phase shift of the detected back-EMF relative to the no-load back-EMF is too large and the control circuit does not take phase-shifting measures, it will affect the output and control performance of the motor.

  There is a literature using magnetic circuit analysis method to analyze the influence of armature reaction of a brushless DC motor with a surface-mounted magnetic steel structure on the phase of commutation electromotive force, and it is verified by experiments. When the motor speed is 3000r/min and 6000r/min, the phase shift of the detected electromotive force caused by the corresponding armature reaction is 11.61 and 11.05, respectively.

  This article is taken from ------"Permanent Magnet Brushless DC Motor Technology"