Effect of 48 V Mild Hybrid System Layout on Powertrain System Efficiency and Its Potential of Fuel Economy Improvement

2017-01-1175

03/28/2017

Features
Event
WCX™ 17: SAE World Congress Experience
Authors Abstract
Content
Recovering as much braking energy as possible, and then fully reusing it, can significantly improve the vehicle powertrain efficiency, hence reducing the CO2 emissions and fuel consumption. A 48 V mild hybrid system recovers less braking kinetic energy than a HV (High Voltage) hybrid system due to the reduced peak power/current rating. However, the cost of the 48 V mild hybrid system is significantly less than the HV hybrid system which gives the 48 V mild hybrid system a much better cost-benefit ratio. The 48 V mild hybrid system can have several different system layouts (e- machines at different positions, or have numerous e-machines at different position combinations). The aim of this study is to investigate and explain how the system layout affects the powertrain system efficiency and CO2 benefit. Simulation models are used to predict the CO2 of three such configurations. The paper starts with the summary of the 48 V mild hybrid system layouts and an introduction of the possible 48 V mild hybrid system operating modes. Due to the energy flow through different components in each layout, an analysis is presented to compare the powertrain system efficiency of each layout under different operating modes. Then, the suggestions of the most cost effective 48 V mild hybrid systems (based on the different operating mode requirement and vehicle mass) are presented. Finally, several 48 V mild hybrid system layouts and their characteristics are discussed as examples.
Meta TagsDetails
DOI
https://doi.org/10.4271/2017-01-1175
Pages
11
Citation
Bao, R., Avila, V., and Baxter, J., "Effect of 48 V Mild Hybrid System Layout on Powertrain System Efficiency and Its Potential of Fuel Economy Improvement," SAE Technical Paper 2017-01-1175, 2017, https://doi.org/10.4271/2017-01-1175.
Additional Details
Publisher
Published
Mar 28, 2017
Product Code
2017-01-1175
Content Type
Technical Paper
Language
English