Electrification Strategies and Power Distribution Method for Commercial Semi-Trailer

Hybrid Electric Vehicle (HEV) is the transition from conventional to electric vehicles, with the advantages of great power characteristics and low polluting emissions. A new hybrid power system was investigated by installing a motor on the axle of a conventional semi-trailer. The purpose is to reduce the fluctuation of longitudinal acceleration and improve driving comfort by filling the transmission output torque hole through the motor during the gear shift process. Models for the longitudinal motion of a commercial vehicle, the permanent magnet synchronous motor, and the motor power distribution method are established, and the system model is built using MATLAB/Simulink. The model-in-the-loop simulation control interface is created in ModelBase, and model-in-the-loop simulation under the full-throttle(WOT) and braking operating conditions is performed based on ModelBase. Due to the high-frequency jitter problem in the actual control of the motor, the torque output obtained from different control algorithms is investigated. Finally, the sliding mode control algorithm with perturbation observation is used to ensure the fast response and smoothness of the motor torque output. The power is distributed based on the vehicle speed, longitudinal acceleration, and vehicle pedal information to determine the motor's operating mode. The dynamic performance of the two systems is compared under the given operating conditions. The results show that the longitudinal acceleration fluctuation is reduced by 30-40% under full throttle condition, and the electric motor can improve the vehicle's dynamic performance and driving comfort. In the braking condition, the electric motor acts as a retarder to enhance the braking performance.