Open AccessAnalytical modelling of the effect of pole offset on the output parameters of BLDC motor
Author(s) -
Jafarboland Mehrdad,
Sargazi Mostafa Miri
Publication year - 2018
Publication title -
iet electric power applications
Language(s) - English
Resource type - Journals
ISSN - 1751-8679
DOI - 10.1049/iet-epa.2017.0703
Subject(s) - cogging torque , offset (computer science) , air gap (plumbing) , control theory (sociology) , magnet , counter electromotive force , physics , torque ripple , mechanics , ripple , mathematical analysis , finite element method , torque , magnetization , dc motor , magnetic field , mathematics , materials science , computer science , voltage , induction motor , direct torque control , control (management) , quantum mechanics , artificial intelligence , composite material , programming language , thermodynamics
In this study, a new analytical model is provided to calculate the effect of the pole offset on the output parameters of brushless DC (BLDC) motor. The proposed model is based on the two‐dimensional analysis model and the direct solution of Laplace and Cauchy–Poisson equations for the magnetic field in the air gap and the magnets area. In this model, radial and tangential components of the magnetisation vector are calculated. Effect of pole offset on the radial and tangential components of magnetisation vector is derived. It is shown that in the case of a motor with pole offset although the length of the magnet decreases at the edges of the pole, the effective air‐gap length remains constant. This study proposed two coefficients to model the reduced thickness of the magnets at the edges of the poles. Therefore, the flux density is calculated in the air gap and motor magnets. Based on the proposed model, effect of pole offset on the cogging torque ripple and back‐electromotive force is achieved. These results are compared with the results of finite element and experimental tests and accuracy of the model is presented.