Design of Electric Vehicle Two-speed Transmission Ratio based on NEDC

Abstract

Aiming at the design of transmission ratio for two-speed transmission of pure electric vehicle， under the condition that parameters of vehicle and motor are all determined， choosing the transmission ratios as the design variables， the optimization objective function and constraint conditions are established according to the power consumption of 100 kilometers under NEDC(The New European Driving Cycle) working condition and the dynamic performance design requirements of vehicle， then the improved harmony search algorithm is used to calculate the optimal solution of the optimization model under constraint conditions. The result shows that the selected two-speed transmission basically meets the design requirements. Compared with the original single-speed transmission， the design results obtained by this method improve the economy of the vehicle to a certain extent.

Keywords

• NEDC working condition