Electric drive dimensioning for a hybrid working machine by using virtual prototyping

Designing the drive train for a hybrid working machine necessitates totally new methods compared to traditional diesel operated working machine design as dimensioning the diesel, the energy storage and the electric drive is much more complicated than just selecting the diesel according to the peak power demand as in traditional ICE drives. Preparing a prototype is a time and other resources consuming way and something else should be offered for the task to speed up the process. Virtual prototyping, software-in-the-loop (SIL) and hardware-in-the-loop (HIL) methods might speed up the hybrid drive design in a significant way. In this paper we present a method for working machine virtual prototyping and testing. A mechanical model of the working machine is running in a simulator designed specifically for modelling working machines. The human-machine interface (HMI) with important visuals and movement feedback emulating the real driving feeling is a key component in the SIL and HIL simulator enabling virtual testing of the working machine designed. The electric drive control software and the electrical motor model are running in another application in the SIL case and later real drive components are tested in the HIL case. The applications are connected together via TCP-IP protocol enabling even longer distances between the components. The presented method is used to dimension the drive train components in a hybrid working machine.