Der Einfluss von 48 V auf Grundmotorreibungsund Effizienzoptimierung – Ansatz zur Quantifizierung in zukünftigen Fahrzyklen

To achieve fleet fuel consumption legislation of 95g/km CO₂ in 2020, various electrification measures will be introduced, besides engine measures, to reduce the overall energy demand of the vehicle. The introduction of 48V electrical architecture provides increased electric recuperation and limited electric driving at lower cost compared to full hybrid solutions, offering considerable fuel reduction potential in the WLTC.Current belt starter-generator systems already realise direct recuperation and torque boost functions. Additionally they can support a highly effective electrical supercharging system which is clearly superior to current multi-stage turbocharging concepts, particularly in transient response. With flywheel starter-generator concepts, additional functions open up such as purely electric driving in a limited range, or simplification of the base engine towards the goal of a beltless engine. Demand controlled, electrical auxiliaries are already in series production for the cooling-, vacuum- or air conditioning systems. Additional areas of interest are the oil system and variable elements in the valve train or crank train.The optimum balance of electrical and mechanical functions on the base engine and its periphery requires an application dependent evaluation with the aim of minimized overall system complexity and cost as well as added customer value.In this paper, the effects of friction and power loss of electrified components are investigated in detail for the relevant driving conditions, especially when consequently implemented into a dedicated 48V base engine with the aim of a modular functional integration.