Simulation model for a serial hybrid bus and impact of energy management on fuel consumption

A simulation model for a serial hybrid bus in Matlab/Simulink is described. The model is a compromise between a low model complexity and a sufficient accuracy of the results. The electrical traction motors and the generator are modeled by static loss models and with dynamic thermal multi-body models. The static loss models are used to determine the efficiencies and the thermal multi-body models are used to determine the temperature of the components. The inverters of the traction motor and the generator are modeled with a static loss model at a constant temperature. The DC/DC-Converter, the gear box and the diesel engine are modeled with efficiency diagrams for one given temperature level. With this model it is possible to estimate the power demand and the electrical energy usage of the drive train components as well as the fuel consumption of the whole bus for a given track and load cycle. Hence the components of the drive train can be dimensioned properly, and the energy management can be optimized.