Direct Liquid Cooling Method Verified With an Axial-Flux Permanent-Magnet Traction Machine Prototype. - Pia Lindh; Ilya Petrov; Ahti Jaatinen-Varri; Aki Gronman; Miguel Martínez-Iturralde; Marco Satrustegui; Juha J. Pyrhönen (IEEE Trans. Ind. Electron., 2017)