Exploring Optimization Opportunities for Battery Electric Vehicle Compact Powertrains by Enhancing Power Density to Meet Customer Demand

The rapid evolution of battery electric vehicle (BEV) development has highlighted the need to develop BEVs that meet customer demands for both high-performance and space-efficiency. This paper explores the optimization opportunities available within the landscape of BEV powertrains, focusing on the power-dense potential of single-axis powertrain systems. The need to adhere to power density requirements to accommodate performance aspirations while simultaneously yielding more cabin or storage space to the customer creates a challenging problem for designers. With this pursuit, these competing interests must strike a harmonious balance to create the best experience for the customer. The subject of this study is an investigation into a leading competitor's powertrain that explores the potential optimization opportunities available within its already compact single-axis electric transmission. The methodology entails a reverse-engineered model of the geartrain, enabling an outsider’s assessment of the gear durability responses experienced by the actual system. An in-house optimization workflow is then leveraged that can explore the feasibility of further size reduction while upholding the standards exhibited by the existing system. Insights into the workflow process and software employed are presented while analysis of the optimization outputs is examined. In conclusion, the findings provide a glimpse into the ability for the BEV transaxle design process to consider optimization at earlier stages in development. This study aims to highlight the need for continuous improvement in design by addressing the feasibility of attaining a more compact yet resilient powertrain. By leveraging an intelligent optimization workflow, the paper determines whether a compact production powertrain yields any additional room for improvement. With current technological advancements allowing for engineers to simultaneously pursue many competing objectives such as efficiency, NVH, durability, size, and cost into unique workflows, designs that bring the best driving experience for our customers can be delivered.