Accounting for saturation in conformal mapping modeling of a permanent magnet synchronous machine

Abstract

Purpose -In the electromagnetic field simulation of modern servo drives, the computation of higher time and space harmonics is essential to consider appearing torque pulsations, radial forces and ripple torques. The purpose of this paper is to propose a method to cover the effect of saturation on the armature flux density within conformal mapping (CM) by an finite element (FE) re-parameterization. Design/methodology/approach -Field computation by CM techniques is a time-effective method to compute the radial and tangential field components, but it generally neglects the effect of saturation. Findings -This paper presents a method to re-parameterize the CM approach by single FE computations so as to consider saturation in the model over a wide operation range of the electrical drive. Practical implications -The proposed method is applied to a surface permanent magnet synchronous machine, and compared to numerical results obtained by finite element analysis (FEA). Originality/value -The paper shows that an accuracy similar to that of FE simulations can be obtained with still the low-computation time that is the characteristic of analytical models.

An improved conformal mapping method for magnetic field analysis in surface mounted permanent magnet motors

“…The basic assumption of the CM method is the constant relative permeability of the core. The saturation effect modeling in the CM method has been assumed to be negligible in all previous publications other than (Hafner et al, 2011;Hanic et al, 2016). In Hafner et al (2011), a technique was proposed to include the saturation effect on the armature flux density in the CM method by finite element re-parameterization (in frequency domain).…”

“…The saturation effect modeling in the CM method has been assumed to be negligible in all previous publications other than (Hafner et al, 2011;Hanic et al, 2016). In Hafner et al (2011), a technique was proposed to include the saturation effect on the armature flux density in the CM method by finite element re-parameterization (in frequency domain). However, this method has two main defects: first, it does not consider the effect of no-load flux density and second, this proposed technique is FE dependent.…”