Analysis and Simulation of Fuel Consumption and Energy Throughput on a Parallel Diesel-Electric Hybrid Powertrain

Abstract: The aim of this master thesis is to study the energy throughput and fuel consumption of a paralleldiesel-electric hybrid vehicle. This has been done by utilising a software model of such a vehicleto simulate the results of alterations of variables believed to affect energy throughput and fuelconsumption as well as other parameters of interest. These parameters are selected depending ontheir relative importance when it comes to hybrid technology and the power sources of such avehicle; the diesel engine, the electric machine and also the battery.For obvious reasons it is important to focus on reducing fuel consumption but in an overallperspective it is also vital to understand how parameters related to the battery state can beaffected and how the battery lifetime can be increased. Thus the key parameters in this study areenergy throughput, fuel consumption, battery state of health (SOH) and state of charge (SOC),powertrain modes and drivability. Further, analyses of total used energy, costs and CO2 emissionshave been made. The alterations have been made to dataset variables mainly affecting the torquedistribution between the diesel engine and the electric machine and to other variables believed toaffect the selected key parameters.The results show that for most variable alterations a weighting needs to be done as to the relativeimportance of reducing either the energy throughput or the fuel consumption since these mostoften change in opposite directions as the altered variables are simulated. The results cannevertheless be used as indications for how certain vehicle data alterations affect the abovementioned key parameters. It is shown that the alterations lead to reduced energy throughputmore often than they lead to reductions in fuel consumption. One variable alteration howeverleads to decrease of both these two main key parameters, namely reduced maximum torque fromthe electric machine (EM). When it comes to sustainable development and CO2 emissions it canbe concluded that the main source of emissions are from the diesel fuel consumption.