Shifting strategy and energy management of a two-motor drive powertrain for extended-range electric buses

摘要

This paper studies the shifting strategy and energy management of a two-motor drive powertrain for extended-range electric buses. To do this, a multibody dynamic model is first established for transient investigation. A novel shift schedule is second proposed by integrating a priority factor for the engaging gear into the equivalent motor efficiency. According to vehicle speed and power, the shift schedule results in two possible cases: single-gear and double-gear change. Optimal shifting strategies are third recommended to eliminate the torque interruption under those possible gear changes. To optimize the torque allocation to two motors and minimize fuel consumption, a model predictive control-based energy management strategy is then developed. Finally, this paper simulates shift quality and energy economy in comparison with a conventional one-motor drive powertrain. The results show that torque interruptions generate large jerks in the one-motor configuration. Conversely, the two-motor configuration achieves great shift quality by eliminating the torque interruptions mostly during single-gear upshift or entirely under double-gear downshift. The two-motor drive powertrain also improves energy economy significantly by 9.1% compared to the conventional configuration. (C) 2020 Elsevier Ltd. All rights reserved.