 Abstract --Cost and compactness are major success factors for electrical drivetrains for (hybrid) electric vehicles (EV). To increase the system power density, the focus is set on system integration, meaning to integrate emachine, inverter, control, and gearing into one common housing. The inverter integration is facilitated by multiphase motors leading to lower phase powers and thus smaller inverter modules. To overcome price uncertainties of rare earth magnets, improved hard ferrite magnets are chosen as an alternative. In this paper, a new highly integrated drivetrain with a ferrite based 9-phase synchronous motor concept is presented with special focus on the main choices leading to the particular electromagnetic and mechanical design. The advantages of an integrated triplex inverter power supply and the new mechanical arrangement of a spoke-type rotor design will be presented, without focusing on the detailed electromagnetic behavior of the machine.

A direct cooling design using hollow conductors with the coolant flowing inside can significantly improve the heat dissipation in an electrical machine. To predict the thermal performances of an electrical machine with such cooling configuration, this paper proposes a computationally efficient thermal model of hollow conductors with direct cooling features. The hollow conductor is modelled using four equivalent solid cuboidal elements with a three dimensional thermal network and internal heat generation. The heat transfer coefficient between the coolant and conductors is determined by an empirical model considering fluid dynamics behaviors. Axial discretization is performed to take into account the non-uniform temperature distribution along the axial direction. Experimental validation is performed with a U-shaped hollow conductor test rig. Compared to computational fluid dynamics analysis, the proposed thermal model is much more computationally efficient, and thus can be incorporated into design optimization process and electro-thermal simulations of the electrical machine over a driving cycle. Index Terms-Thermal model, hollow conductor, direct cooling, electrical machine.

In this paper the optimization of a transverse flux induction heating device by means of a parameter-free, self-adaptive particle swarm optimizer is presented. The novelty of this work is represented by the fact that concentric multi-coil induction heaters have never been optimized before in their full three-dimensional complexity. The main technical challenge of the problem consists in designing a single configuration capable of heating strips of different widths while satisfying geometrical, electrical and heating process constraints. It will be shown that a system consisting of three coils can successfully heat strips of widths between 600 mm and 800 mm with the required uniformity

This paper shows a new concept to generate medium voltage (MV) in wind power application to avoid an additional transformer. Therefore, the generator must be redesigned with additional constraints and a new topology for the power rectifier system by using multiple low voltage (LV) power rectifiers connected in series and parallel to increase the DC output voltage. The combination of parallel and series connection of rectifiers is further introduced as DC-cascade. With the resulting DC-cascade, medium output voltage is achieved with low voltage rectifiers and without a bulky transformer. This approach to form a DC-cascade reduces the effort required to achieve medium DC voltage with a simple rectifier system. In this context, a suitable DC-cascade control was presented and verified with a laboratory test setup. A gearless synchronous generator, which is highly segmented so that each segment can be connected to its own power rectifier, is investigated. Due to the mixed AC and DC voltage given by the DC-cascade structure, it becomes more demanding to the design of the generator insulation, which influences the copper fill factor and the design of the cooling system. A design strategy for the overall generator design is carried out considering the new boundary conditions.

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