Efficiency Measurements and Lubricant Optimization in Electric Drives

This technical report investigates the influence of lubricant composition and physical properties on the efficiency of wet coil Electric Drive Units (EDUs) under various operational conditions. The study is partially funded by the German Federal Ministry for Economic Affairs and Climate Action as part of project CHEPHREN. It highlights the growing electric vehicle (EV) sector in India, which is projected to expand significantly, creating opportunities for lubricant development. The research details experiments conducted with different lubricant options, focusing on kinematic viscosity, viscosity index, and base oil types. Results indicate that reducing lubricant viscosity can enhance efficiency during Worldwide Harmonized Light Vehicles Test Procedure (WLTP) cycles. The findings suggest that increasing the viscosity index of certain oils can yield similar efficiency improvements without compromising durability. This study aims to provide guidelines for lubricant formulators to optimize viscosity profiles, thereby promoting sustainable electric mobility and potentially lowering costs for consumers while enhancing the overall value proposition of EVs.