Performance and Fuel Economy Analysis of a Mild Hybrid Vehicle Equipped with Belt Starter Generator

摘要

This thesis focused on the study of a hybrid electric vehicle equipped with a belt starter generator, or BSG. With this system, the conventional starter and the alternator are replaced by one electric machine only, capable of cranking the engine, charging the batteries and supplying the on-board electric loads. These characteristics allow the introduction of new functionalities, including engine stop-start, regenerative braking, and electric assist. The purposes of the research were two: the assessment of the stop-start performance and the evaluation of the fuel consumption reduction that can be achieved with this system compared to a conventional vehicle. Simulink models of the powertrain were used to obtain the results, which were validated against experimental data from a start cart and a real proof-of-concept vehicle. The results illustrated the critical factors affecting the stop-start performance, and demonstrated that remarkable fuel savings can be obtained with the BSG, especially for city driving.