Economy Performance Simulation and Test Validation of a Sample Vehicle with Two-Speed Dedicated Electric Transmission

Multi-speed transmissions can improve power and economy performance of battery electric vehicles (BEVs), thus becoming an inevitable trend in automotive industry. A two-speed dedicated electric transmission (2DET), which can realize switching of two gear ratios through two wet clutches, is explained firstly. Secondly, 2DET is developed and a prototype is assembled in a BEV of Beijing Electric Vehicle Co. Ltd. (BJEV). Thirdly, the differences of new European driving cycle (NEDC) and China light duty vehicle test cycle passenger (CLTC-P) are compared. Fourthly, the parameters of battery cell are tested and a simulation model of the whole vehicle with 2DET is built. Finally, vehicle economy performance under NEDC and CLTC-P is simulated, and the results are validated in bench tests. Comparison shows that the economy simulation results match the test results, and the vehicle economy under CLTC-P is better than NEDC, with an increase of 1.16%.