Electromagnetic and thermal homogenisation of an electrical machine slot

Abstract

In this paper we propose an original technique based on the finite element method to couple electromagnetic and thermal homogenisation of multiturn windings. The model accurately accounts for skin and proximity effects considering the temperature dependence of electrical resistivity. We validate the approach by modelling a reference electrical machine open slot with representative boundary conditions. The case study refers to a particular wire shape and winding periodic configuration but the method can be applied to any symmetrical wire shape. The homogenisation allows us to efficiently evaluate the hotspot temperature within the slot. The solution provided by the homogenised model proves to be very accurate over a large range of frequencies, when compared to the results using a fine model where all the conductors are physically reproduced. projects on fast electrochemical modelling, modelbased battery management systems, battery thermal management, battery degradation and motor thermal management and degradation. His research interests include condition monitoring and management of electric-vehicle components.

Analysis of Electrothermal Homogenization for the Fast and Accurate Modeling of Windings in Power Electronics Magnetic Components

“…or by means of the homogenised model in Section II. The losses in the homogenised winding window Ω ww are calculated from the real part of (2), i.e., skin-effect losses, and the imaginary part of (3), i.e., the proximity-effect losses, as [13]:…”

“…Homogenisation models including both the electromagnetic and thermal aspects are much less common [1], [13]. This work aims at the analysis of accurate electromagnetic homogenisation techniques combined with thermal homogenisation approaches.…”

Influence of Insulation Thermal Aging on the Temperature Assessment in Electrical Machines

“…The same procedure needs thus to be repeated for each of the slot nodes (according to the chosen discretization level). In the proposed LPTN, the slot has been thermally homogenized and modelled as a compound of two materials [24][25][26], namely copper and impregnating resin. Thus, its equivalent thermal conductivity, in both radial and tangential directions, is calculated according to (3) [24], where ff is the copper fill factor, while kcu and kres are the copper and impregnation resin thermal conductivities respectively.…”

3D homogenisation of concentrated windings with rectangular conductors

“…Due to its straightforward implementation, in this work we employ and extend the method described in [10]. Compared to [14,15], here we show how to apply the method to a 3D domain with no axi-simmetry, including thermal effects; extensive experimental validation is also provided. The techniques is applied to an hardware exemplar of an open-slot modular stator-winding assembly with profiled conductors (from now on referred to as "motorette"), see Fig.…”

“…It is important to notice that the effective resistivity results in an effective impedance Z eq to be included in the external electrical circuit equations. Moreover, as shown in [14], the parameters presented in Fig. 2(b) include a thermal effect if the temperature dependence of electrical conductivity is captured with the linearised formula…”