A novel motor torque distribution strategy for distributed-drive
electric vehicle considering energy saving and brake stability 2019-01-0334
This paper presents a novel torque distribution strategy (TDS) for distributed-drive electric vehicle (DDEV) with respect to energy saving. The presented TDS can not only minimize energy consumption from battery in driving process, but also maximize energy regeneration to battery in braking process. First, the energy saving evaluation index and objective function are defined. The objective function is defined as the total power of four motors, which is determined by torque distribution ratio when current desired total torque and vehicle speed are given. Second, a novel optimization algorithm is proposed to obtain the optimal torque distribution ratio of front and rear axles according to current total torque demand and vehicle speed based on motor efficiency map. Particularly, the optimization algorithm takes ECE regulation into account to satisfy braking stability requirements when the vehicle is in braking process. In order to improve execution speed, the optimization result for every achievable motor operation point is expressed using a 3-dimension look-up table. Finally, co-simulation experiments based on Carsim and Simulink are carried out to verify the effectiveness of the proposed torque distribution method under NEDC and UDDS driving cycle. The simulation results show that the proposed TDS method improves the energy efficiency and energy recovery than even-wheel drive and front-wheel drive.
Jingxing Liu, Hong Zhong, Liangmo Wang, Hejuan Chen
Nanjing Univ. of Sci and Tech., Univ of Michigan-Ann Arbor, Nanjing Univ of Science & Technology