Study On Drive Control Strategy For A Novel Dual-Motor Coupling Powertrain

In recent years, energy saving and high efficient electric vehicles(EVs) have become the research hotspot. Powertrain is an important component of EVs, which mainly consists of motor-driven systems, mechanical transmission systems, and other components. However, with the deepening study of the powertrain, its low energy utilization and high cost become increasingly prominent, which has a serious impact on the vehicle’s power and economy, and restricted the development of EVs. Therefore, the R&D of high performance and low cost powertrain is one of the key technologies for EV industrialization.For the above problem, based on a novel dual-motor coupling powertrain(DMCP) with planetary and fixed gears, the following studies were undertaken in this paper:① Analysis of system dynamic of DMCP in different modesAccording to meet the demands of driving range and dynamic performance, considering the possibility of mode shifting without power interrupt, parameter selection of battery, electric motor and mechanical transmission systems is finished, and vehicle dynamic performance simulation is implemented.② Parameter matching of DMCPBased on the structure characteristics of dual-motor coupling EV powertrain, DMCP could have four driving modes: single motor 1, single motor 2, torque coupling and speed coupling, and the dynamic characteristic is studied in this paper through lever diagram.③ Study on energy management strategy of DMCPThe optimized mode and power split plan in any vehicle speed, acceleration and SOC scopes are calculated, respectively, and the control strategy is made up. Detail DMCP facing-backward transmission simulation model is developed by using Simulink, with which the range simulations with a 60-km/h constant speed and NEDC, 10-15, and UDDS driving cycles are implemented. By comparing with a two-speed AMT EV with identical power, the DMCP has longer driving range than it.④ Study on mode shifting control strategy of DMCPBased on the structure characteristics of dual-motor coupling EV powertrain, a set of mode-shift control strategy is set out, with the detail facing-forward transmission simulation model developed by using Simulink, and twelve possible mode-shift process are analyzed and simulated and the result shows that DMCP can shift mode without dynamic power interrupt and with limited jerk degree.