2013 Eighth Intenational Conference and Exhibition on Ecological Vehic1es and Renewable Energies (EVER) Transient Thermal Analysis of Flux Switching PM machines E. Ilhan, M. . J. Kremers, . E. Motoasca, J. J. H. Paulides and E. Lomonova Department of Electrical Engineering, Electromechanics & Power Electronics (EPE) Group, Den Dolech 2, 5612 AZ Eindhoven, The Netherlands Email: e.ilhan@tue.nl Absract-Flux switching permanent magnet (FSPM) ma chines bring together the merits of switched reluctance and PM synchronous motors. FSPM employs armature windings and PMs together in the stator egion, therefore the proximity of the windings and PMs makes a thermal model mandatory. In literature, thermal modeling of the FSPM is not addressed exteusively compared to its electromagnetic modeling. With this aim, irst a steady-state TEC model is created for a 3-phase 1/10 FSPM. Additionally, conformal mapping, in particular Schwarz Christofei, is used to increase the accuracy of the TEC model. Using Laplace transformation, the steady-state model is extended to a transient thermal model. Results are compared and validated by the inite element method. Stator teeth Stator __ II .. Rotor Fig. 1. 3D illustration of a FSPM wih 10 rotor and 12 stator poles. I. INTRODUCTION Flux Switching Permanent Magnet (FSPM) machines are favoured in automotive industry due to their high torque-to volume ratio (torque density) and robust rotor structure. As with all electrical machines, the torque density strictly depends on the thermal limits of the machine. In the literature, various work on the FSPM is based on the electromagnetic analysis as in [1]-[4] with little emphasis given on its thermal modeling [5], [6]. Thermal modeling plays an important role in the design process of an electrical machine to set the operation limits and the choice of insulation c1asses [7], [8]. Both analytical and numerical methods can be used to model the steady state and transient heat low in the machine. Although advanced numerical models make use of the equations of luid dynics and thermodynics, for electrical machine analysis, a more practical method is based on the analogy between thermal and electrical circuits is used [9]-[12]. In FSPMs, armature windings and PMs are both placed in the stator section. Due to this proximity, developing a thermal model becomes mandatory along with an electromagnetic model for the design and analysis of a machine. In this paper, a thermal equivalent circuit (TEC) model is created to analyse for the steady-state and transient thermal behaviour of the FSPM. It is also shown, how to implement conformal mapping (Schwarz-Christofel mapping) in the TEC model to increase the model accuracy. For the transient model, the resulting diferential equations are solved by Laplace transformation, which enables the use of direct matrix manipulations instead of time dependent equations. Analytical results are veriied by the 2D thermal Finite Element Model (FEM) simulations. 978-1-4673-5271-0/13/$31.00 ©2013 IEEE Fig. 2. TEC model of FSPM.