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This paper focuses on the electromagnetic design and experimental evaluation of an electrically magnetized permanent magnet assisted synchronous machine (EMPMSM). The work is carried out on an existing Lundell alternator where the design of the rotor facilitates features of field strengthening and weakening operation possible including the efficiency improvement. A relatively simple and compact slip ring less rotor with EM and PM excitation is proposed, analysed and tested. A series of 3D FE transient computations are made in order to estimate efficiency at different operation points and with different types of rotor cores: solid iron and powder core. A rotor with the solid iron core is built and tested including different aspects of torque and power loss production. Index Terms-Design of electrical machines, 3D finite element transient analysis, synchronous machines, soft magnetic materials:

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Effectively removing dissipated heat from the switching devices enables a higher current carrying capability per chip area ratio, thus leading to smaller or fewer devices for a given power requirement specification. Further, the use of SiC based devices has proven to increase the efficiency of the system thereby reducing the dissipated heat. Thermal models have been used to compare SiC power modules. Single and double sided cooling have been simulated. The simulated maximum temperatures were 141 °C for the single sided version and 119.7 °C for the double sided version. In addition, the reliability of a single sided module and thermally induced plastic strains of a double sided module have been investigated. A local model of the wire bond interface to the transistor metallization shows a 30/00 maximum increase in plastic strain during the power cycle. Simulations of the creep strain rates in the die attach solder layer for a power cycling loads also shows a 30/00 increase in creep strain per cycle