Study of the Influence of Steel Saturation on the Spatial Harmonic Fields of the Stator in the Machine Air Gap

Abstract

Relevance: the performance of alternating current electrical machines largely depends on the characteristics of the magnetic field in the air gap, including its spectral composition. One of the factors influencing the field distribution is the magnetic core steel saturation. Although this effect has previously been studied in the context of integral machine parameters, its influence on the spatial harmonics of the field—especially in machines with a fractional number of slots per pole per phase—remains insufficiently explored. Considering magnetic saturation in harmonic analysis makes it possible to refine calculations of torque pulsations, noise levels, and heating. Therefore, the development of models that reflect the influence of saturation on the magnetic field spectrum is of great interest for more accurate design and simulation of electrical machines.

Aim: to investigate the influence of magnetic core steel saturation on the spatial harmonic components of the magnetic field in the air gap of alternating current electrical machines, taking into account the winding configuration and magnetic material properties.

Methods this study employs analytical and numerical modeling methods to analyze the distribution of the magnetic field in the air gap of alternating current electrical machines, considering the saturation of the stator and rotor core steel sections.

Results: it has been established that saturation of the stator and rotor steel significantly reduces the amplitude of the fundamental harmonic component of the magnetic field in the air gap. When the equivalent magnetic permeability decreases from μ = 4000 to μ = 100, the fundamental harmonic amplitude drops by a factor of 1.5.