Multi-Objective Optimization Considering Battery Degradation for a Multi-Mode Power-Split Electric Vehicle

Abstract

A multi-mode power-split (MMPS) hybrid electric vehicle (HEV) has two planetary gearsets and clutches/grounds which results in several operation modes with enhanced electric drive capability and better fuel economy. Basically, the battery storage system is involved in different operation modes to satisfy the power demand and minimize the fuel consumption, whereas the complicated operation modes with frequent charging/discharging will absolutely influence the battery life because of degradation. In this paper, firstly, we introduce the solid electrolyte interface (SEI) film growth model based on the previous study of the battery degradation principles and was verified according to the test data. We consider both the fuel economy and battery degradation as a multi-objective problem for MMPS HEV by normalization with a weighting factor. An instantaneous optimization is implemented based on the equivalent fuel consumption concept. Then the control strategy is implemented on a simulation framework integrating the MMPS powertrain model and the SEI film growth map model over some typical driving cycles, such as New European Driving Cycle (NEDC) and Urban Dynamometer Driving Schedule (UDDS). Finally, the result demonstrates that these two objectives are conflicting and the trade-off reduces the battery degradation with fuel sacrifice. Additionally, the analysis reveals how the mode selection will reflect the battery degradation.

Research on Adaptive Two-Point Energy Management Strategy and Optimization for Range-Extended Electric Vehicle

“…The improvement of R-EEV performance not only requires to ensure higher energy efficiency but also lower emission and longer battery life as far as possible, and some previous researches on R-EEV have already concerned the MOO problem. Battery performance makes a great difference to the various performances of R-EEV, and the charging and discharging mode of battery determines the battery life [32]. Taking battery life as a consideration, this paper designed an EMS for vehicles.…”

Model-Based Double Closed-Loop Coordinated Control Strategy for the Electro-Mechanical Transmission System of Heavy Power-Split HEVs

“…Recently, the power-split HEVs, especially heavy power-split HEVs, have been widely studied owing to their unique advantages. However, there are three key problems to be addressed for power-split HEVs [4][5][6]: improving the accuracy of power distribution among different power sources, increasing the response speed of the transmission system, and reducing the system fluctuation due to the internal combustion engine (ICE). To solve these problems, much research has been performed.…”

Study of the Energy Conversion Process in the Electro-Hydrostatic Drive of a Vehicle

“…Hence, the electric energy losses (e.g., on the electric battery, wires) in the installation of hybrid drive are significantly lower. Additionally, lowering the value of current intensity flowing through the battery contributes to its durability and reliability [17,18]. The obtained results of the experimental research require an additional word of comment.…”