Optimised Performance of Electric Vehicle with Two-Speed Transmission System based on a Novel Gearshift Strategy

Offering desired performances at minimum energy consumption, a multi-speed transmission system in electric vehicles is associated with several unavoidable complexities. In this study, a three-parameter gearshift strategy has been presented based on vehicle speed, acceleration, and road grade. The gear ratios and the gearshift maps were optimised implementing the gradient descent and pattern search methods. Showing the similar performances on straight road compared to those using the conventional approaches, the proposed gearshift strategy could save approximately 16.5% energy consumption on an inclined road. After a thorough analysis, it was found that the experimental results supported the simulation findings.