Analytical modelling and prototyping a slotless surface‐inset PM machine

Abstract

An analytical model is proposed for the prediction of the no-load air gap magnetic flux density and the armature reaction in the slotless surface-inset PM machines. For this purpose, the exact 2D solution of the Poisson equation is derived. In the modelling process, the rotor salient poles are taken away and some surface magnetisation currents are considered at the borders of the removed salient poles. The contribution of this work is finding the value of the surface magnetisation currents such that the rotor saliency is accurately considered. The field solution in the provided surfacemounted PM machine is simply obtained by the separation of variables method. The machine back-EMF and its inductances is obtained by the predicted flux density due to the PMs and the stator currents, respectively. In addition, using the resultant air gap flux density in the Maxwell stress tensor, the developed electromagnetic torque is computed. Finally, the ability of the proposed model is evaluated by finite element analysis as well as experimental tests.

Analytical modelling and optimisation of line start LSPM synchronous motors

“…In the literature, the analytical modelling of LSPM motors is mainly conducted in either transient [17][18][19][20][21] or steady-state domains [22][23][24][25][26][27][28][29][30]. In [19,20], a dynamic analytical model of a 1phase LSPM motor with the starting capacitor is presented.…”

General Analytical Magnetic Model for Partitioned-Stator Flux-Reversal Machines With Four Types of Magnetization Patterns

“…Various 2-D analytical models have been presented for different types of electrical machines such as rotary with inner rotor [18,22,23,25], [27][28][29][30][31][32][33][34][35][36][37][38][39][40] or outer rotor [21,24,41], planar [42] and axial machines [43], to obtain electromagnetic quantities such as electromagnetic torque or force, inductances, induced voltage and core losses [21,29,31,39]. In some papers, the presented 2-D analytical models are employed to optimally design an electric machine [23,32,35].…”

Analytical model for armature reaction of outer rotor brushless permanent magnet DC motor

“…Many scholars have made their contributions to the analytical calculation of the armature reaction magnetic field in PMBLDCM [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. In order to solve the problem of analytical calculating the air-gap magnetic field of slot effect, there are two main methods used by scholars: direct method and indirect method.…”

“…Akbar and Tthodosios [4,5] used subdomain technology to calculate the armature reaction magnetic field of surface-inset permanent magnetic slotless brushless motor, then the expressions of armature reaction magnetic field of outer rotor and internal rotor were obtained, after that A and B established two-dimensional analytical model of armature reaction field for PMBLDCM, which is suitable for DC and AC motors, and calculated the selfinductance and mutual inductance of armature. Samad and others established the two-dimensional analytical model for the armature reaction field, respectively, for the no-loaded surface embedded brushless motor and the radial flux permanent magnet motor [6,7]. Kesavan et al used the Schwarz-Christoffel transform to calculate the armature reaction field of the outer rotor permanent magnet motor [8].…”

“…For the outer rotor PMBLDCM, the effect of stator slot on the no-load air-gap magnetic field is different between the outer rotor and the inner stator. Yet as for an analytical calculation of no-load magnetic field of outer rotor PMBLDCM, existing researches [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] proposed analytical model failing to reveal the effect of stator slotting effect for armature reaction magnetic field on the outer rotor and inner stator, and failing to reveal the armature magnetic field of the outer rotor and inner stator of the spatial order characteristics and frequency characteristics. In addition, the diversity of the combination of the poles and slots in the PMBLDCM leads to the diversity of armature reaction magnetic field distribution.…”