Crucial parameters design and control for a novel dual-motor powertrain in electric vehicles

Energy efficiency and dynamic performance are critical for electric vehicle powertrains. This paper proposes and investigates a novel dual-motor Ravigneaux planetary gearset powertrain (DMRGP). The layout and working principles of the DMRGP are introduced, and its mathematical model is derived. To explore its potential performance, a parameter optimization method is developed that involves separating design variables; parameters related to the motors are processed using a grid enumeration method, while those associated with the planetary gearset are optimized through a genetic algorithm. This approach ensures a comprehensive search range while reducing optimization time. After completing the parameter optimization, comparative analysis against a benchmark dual-motor configuration highlights the energy efficiency advantages of the DMRGP, demonstrating energy savings of 7.3 % in the CHTC cycle and 6.8 % in a real-vehicle data testing cycle, with an overall saving exceeding 5 % even when considering motor idle losses. Furthermore, a multi-mode shifting strategy is designed that categorizes all shifting procedures based on braking presence to establish constant output torque strategies and power flow-based strategies. This strategy is validated through hardware-in-the-loop experiments, achieving uninterrupted driving torque while maintaining jerk below 10 m/s3. This study offers new insights for the design of innovative vehicle powertrains, particularly for commercial transport vehicles focused on system size and energy consumption levels, as well as for high-performance electric vehicles sensitive to mode shifting jerk.