Mild Hybrid Solutions, Concepts and CO2 Effects

Authors

G. Cariccia, S. Brandin, DAYCO EUROPE SRL; A. Tonoli, Politecnico of Turin

Summary

Many mild-hybrid vehicles employ a Belt Starter Generator (BSG) System, also known as a P0 System, to boost engine performance and efficiency. This paper presents a model-based approach to the design of the energy flow manger used to optimize the efficiency of a BSG System. The model considers the efficiency map of the belt drive system, the efficiency of the starter generator (e-machine), the Internal Combustion Engine’s Brake Specific Fuel Consumption (BSFC) and the battery’s State of Charge (SOC). By constructing the vehicles accessory drive (AD) on a bench test that simulates the e-machine and engine torque and speed range, the belt drive efficiency map can be obtained. A complete vehicle model in MATLAB-Simulink and a numerical representation of the AD in Simdrive (a software released by Contecs) are used to design the torque splitting logic, based on a new formulation of the Equivalent Consumption Minimization Strategy (ECMS) and aims to minimize the fuel consumption and CO2 emissions. Bench testing and in-vehicle testing to the WLTP cycle validate the proposed technique.