Scaling the claw pole machine for drive train optimization

Reducing the fuel consumption of vehicles leads often to an optimization task of the complete drive train. A significant influence to the fuel consumption is caused by the energy consumption of electric loads. An oversized generator, to supply the loads, leads to additional weight of the vehicle and additional costs, which should be avoided. To obtain the right size of the generator an analytical scaling approach is derived in this paper that enables to calculate the generator´s parameters for different sizes in a short time, in contrast to FEM (Finite Element Method) simulations. Compared to other scaling approaches several constraints are taken into account, for example a constant operating voltage level of 13.5 Volt. To fulfill this constraint the stator turns must be adapted when the machine size is increased or decreased. The number of turns must be integer which allows only discrete sizes of machines. This reduces the search space of the optimization task significantly. Finally, this paper presents a method for scaling the parameters of the equivalent circuit and it enables to draw phasor diagrams for different scaling factors, too.