Thermal effects of stator potting in an axial-flux permanent magnet synchronous generator. (22nd January 2015)

• Record Type: Journal Article
• Authors: Polikarpova, Mariia; Lindh, Pia; Gerada, Chris; Rilla, Marko; Naumanen, Ville; Pyrhönen, Juha
• Is Part Of: Applied thermal engineering. Volume 75(2015:Jan.)
• Page Start: 421
• Page End: 429
• Publication Date: 2015-01-22
• Subjects: Permanent magnet generator -- Thermal behavior -- Axial-flux machine -- Cooling solution -- High thermal conductivity materials; Heat engineering -- Periodicals; Heating -- Equipment and supplies -- Periodicals; Periodicals; 621.40205
• DOI: 10.1016/j.applthermaleng.2014.09.044
• Languages: English
• ISSNs: 1359-4311

Abstract

Abstract: Axial-flux machines often have certain problems with heat transfer as shrink fitting of the stator core in the housing is not an option, unlike in the case of radial-flux machines. In this paper, we study how potting of the stator affects the thermal behavior of a 100 kV A axial-flux generator. The axial-flux permanent magnet (PM) generator is of a one-rotor-two-stator type construction. A liquid cooling system is applied on the stator frame, and the potting material in the end-winding region thermally connects the end winding to the housing heat sink. The design principle of the cooling system is presented in detail. Simplified thermal models based on Computational Fluid Dynamics (CFD) are used to analyze the temperature distribution through the machine. The theoretical results are verified by measurements. For comparison, one stator of the prototype generator is potted with Ceramacast 675-N material while the other stator is not potted. In each stator there are 14 Pt-100 temperature sensors. As the temperature values between the potted and unpotted stator are compared, it is found that the temperatures differ from each other by approx. 10% at the end windings under load condition. The application of the potting material also provides the rotor cooling. Highlights: We study the potting material application to avoid over temperatures in the machine stator and rotor. The CFD thermal analysis was implemented and described. Two types of the potting materials were analyzed.