Analytical prediction for electromagnetic performance of interior permanent magnet machines based on subdomain model

Abstract

This paper presents an analytical model for the computation of the electromagnetic performance in interior permanent magnet (IPM) machines that accounts for the stator and the complex rotor structure. Using the subdomain method, we propose a simplified analytical model that considers the magnetic properties of the IPM machine. The analytical solutions are derived by solving the field-governing equations in each simple and regular subdomain, i.e., magnet, barrier, air gap, slot opening, and slot, and then applying the boundary conditions to the interfaces between these subdomains. The analytical model accurately accounts for the influence of the interaction between the slots, the relative recoil permeability of the magnets, and the boundary conditions. The magnetic field and electromagnetic performance obtained using the analytical method are compared with those obtained using finite element analysis. Finally, the analytical predictions are compared with the measured data in order to confirm the validity of the methods proposed in this paper.

Analytical modelling for magnetic field of interior permanent magnet synchronous motors accounting for bridge saturation

“…However, the obtained magnetic potential distribution on the outer surface of the rotor under no-load condition is trapezoidal, which neglects the non-linear saturation in the bridge region, leading to a big calculation error between this method and the FEM method. In [15][16][17][18], the equivalent structure of the motor is proposed according to the principle that the air-gap flux is unchanged after the equivalence, which is more convenient to express in polar coordinates. And the air-gap flux density of the motor is obtained by using the subdomain model method.…”

Magnetic Field Analytical Solution for Non-homogeneous Permeability in Retaining Sleeve of a High-Speed Permanent-Magnet Machine

“…The analytical solution is confronted with finite-element method, which confirms validity of the proposed methodology.The available literature on (semi-)analytical technique for PM machine evaluation is extensive, with published papers ranging over twenty-five years, to the best of the authors' knowledge [10][11][12]. Moreover, there is still great effort towards methods with better accuracy and less restricting assumptions [4,[13][14][15][16][17][18][19][20][21][22] to list a few recently published works. Dubas et al [23] realized an overview on the existing (semi-)analytical models in Maxwell-Fourier methods (vis., multi-layer models, eigenvalues model, subdomain technique and hybrid models) with the effect of local/global saturation.…”

“…Further details, advantages and disadvantages of these techniques can be found in [23][24][25]. Ramakrishnan et al [13] presented a comprehensive comparison of analytical methods, where a subdomain technique exceeded the others in terms of accuracy with reasonable calculation time.Furthermore, extending the limitations discussed in [25], recent developments include more realistic geometric structures, such as tooth-tips [14][15][16][26][27][28] or rotor eccentricity [27,29]. Chebak et al [30] and Rahdeh et al [31] defined more realistic magnetic parameters, but in slotless topologies.…”

“…Furthermore, extending the limitations discussed in [25], recent developments include more realistic geometric structures, such as tooth-tips [14][15][16][26][27][28] or rotor eccentricity [27,29]. Chebak et al [30] and Rahdeh et al [31] defined more realistic magnetic parameters, but in slotless topologies.…”