Simulation of the electrical machine's fuel saving potential in parallel hybrid drive trains

The intention of the present paper is to draw a reasonable comparison of two different types of electrical machines for use in a parallel hybrid electric drive train: the induction machine with squirrel cage on the one hand, the permanent magnet synchronous machine on the other hand. Both machine types have been designed for application in a mild hybrid electric vehicle. By dint of simulation models and a full vehicle simulation system the machines were compared on their different loss behavior during several driving cycles to find out which one meets the given demands. Furthermore, an intelligent control strategy was derived and implemented in the simulation system. The strategy selects the adequate driving function in every operating point from several possibilities, e.g. electrical driving. For reaching good compatibility, the control strategy was generalized for a single driving cycle or a certain drive train configuration. It could be shown what amount of fuel saving the parallel hybrid electric drive train is able to offer compared to a conventional one by using different machine types and elementary strategies.