Computational cost‐effective modelling of non‐linear characteristics in permanent magnet synchronous motors

Abstract

Purpose

In the optimisation of electrical drives, the required degree of detail in the simulation increases constantly. Especially, the industrial demand on multi‐objective optimisation craves for highly efficient models. The purpose of this paper is to propose a hybrid model for the computation of the air‐gap field of a permanent magnet synchronous motor (PMSM) combining analytic and numeric methods.

Design/methodology/approach

The classic conformal mapping (CM) approach is improved by the numeric approximation of the required ansatz‐functions. This approach allows to consider the non‐linear permeability of the applied materials and complex geometries. The non‐linear permeance‐function is described by a one‐dimensional wave varying in time and space.

Findings

The permeance‐function has to be derived for different load cases at the actual stage.

Research limitations/implications

A physical motivated modelling allowing for an appropriate interpolation between different load cases is planned in further research.

Practical implications

The proposed approach is applied to a surface mounted PMSM. It is validated by means of a non‐linear finite element analysis.

Originality/value

The hybrid model offers to consider rotors with buried magnets using the CM approach. It is possible to either use analytic or numeric modelling of rotor ansatz‐function, stator current ansatz‐function and permeance‐function with the proposed approach. Non‐linear permeability of iron is modelled by means of a wave representation of the permeance‐function. This can significantly reduce the computational cost in the design and optimisation stage of electrical machines.

Citation

Franck, D., Hafner, M. and Hameyer, K. (2011), "Computational cost‐effective modelling of non‐linear characteristics in permanent magnet synchronous motors", COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, Vol. 30 No. 3, pp. 885-893. https://doi.org/10.1108/03321641111110852