A new hybrid analytical model based on winding function theory for analysis of surface mounted permanent magnet motors

Abstract

Purpose The purpose of this paper is to present an improved winding function theory (IWFT) for performance analysis of surface mounted permanent magnet (SMPM) motors, which can precisely and simultaneously consider the impacts of stator slotting, the winding distribution, the magnetic flux density within PMs because of the armature reaction, the PM magnetization angle and the magnetic saturation,. Design/methodology/approach To obtain this improved analytical model, the conformal mappings (CMs) are introduced to calculate the relative complex permeance of slotted air-gap, which is used to obtain the function of slotted air-gap length. The equivalent magnetizing current model is used to extract the equivalent winding function for each PM pole. For retaining the basic assumption of WFT, the magnetic saturation is also considered by a proper increase in the air-gap length in the front of the stator teeth. Findings A new hybrid analytical model (HAM) based on WFT is presented in this paper, which can simultaneously and accurately consider the effects of slotting, the magnetic saturation, the variation of PM operating point and the winding distribution. In fact, IWFT removes all the drawbacks of the conventional WFT. Moreover, IWFT is more user-friendly and faster than other analytical and numerical techniques. Practical implications The obtained HAM can be used for design, optimization and fault diagnosis in electric machines. Originality/value This paper presents a new HAM for accurate modeling the SMPM motors, which includes different considerations of electromagnetic modeling. This new HAM can also be used for modeling the other electric motors.

Analytical calculation and finite element evaluation of electromagnetic leakage field distribution in surface-mounted permanent magnet synchronous motors taking the rotor eccentricity effect into account

“…Also, there is a third type of unbalanced axis called mixed unbalanced axis faults or mixed eccentricity, which is defined as a combined form of the previous ones. These faults are more observed in practice (Usman et al , 2017; Faiz, 2019).…”

Hybrid winding function method for inductance analysis of a line start synchronous reluctance machine

“…The technique proposed by [11]- [13], reviewed the air-gap permeance function using the MATLAB Schwartz-Christoffel (SC) Toolbox for conformal mapping transformation [14], [22]. The authors propose a numerical identification of the conformal map using the complex transformation technique instead of an explicit Fourier expansion for an accurate profile of the permeance.…”

“…The LSSRM was described almost completely in terms of the geometrical characteristics of its air-gap, such as the air-gap length, slot opening width, and the number of slots. Once the air-gap geometry was defined, the execution of the proposed hybrid winding function theory (HWFT) developed by [11] was used to complete the self and mutual inductance calculation process. At several points, the approach does not require any dealing with complex physics principles involved in the whole LSSRM device structure.…”

Analytical Model of Induction Machines with Multiple Cage Faults Using the Winding Tensor Approach

“…Linear models allow for a further simplification, using a one-dimensional analysis in which the radial component of the flux density is determined as a function of the angular position of the coils along the air gap circumference [ 15 ]. Many formulas for determining the self and mutual inductances of an arbitrary pair of coils situated in the air gap zone have been presented in the technical literature, as in [ 26 , 27 ], and they are the base of the winding function approach (WFA) [ 23 , 28 ]. Nevertheless, this approach requires complex winding functions that depend on the relative position of the coils, on the coils MMF functions, on the permeance function of the air gap, and on the rotor position, leading to triple integrals for each pair of coils [ 15 ].…”