Research On Drive Control Strategy Of Pure Electric Bus

Under the development trend of pure electric vehicles in the world,China’s pure electric vehicle industry is booming.On the one hand,it benefits from the guidance and promotion of the national policies,and on the other hand,it benefits from the successive breakthroughs of various technologies.However,with the gradual decline of new energy vehicle subsidies and the development of power battery technology that cannot break through the bottleneck in the short term,China’s pure electric vehicle industry will enter a new stage of technical challenges,power conversion,and structural adjustment.The control unit of car is most important components for all-electric cars,and the quality of its control strategy is an important factor that determines the vehicle performance.Because drive control strategy is also one of the most basic and important key technologies in vehicle control,so establishing an efficient and perfect drive control strategy for pure electric vehicles is extremely important for improving the power and economy of vehicle.This paper relies on the development project of a complete electric vehicle control system for the pure electric bus(JMV6702BEV),and focuses on the drive control strategy of the entire vehicle controller.Based on the research status of the three key technologies releted to battery,motor and electric control,both the hierarchical modeling research method and the joint simulation technology were used to build a three-layer drive control strategy model.And then it was embed into the vehicle model to complete the joint simulation experiment.At the same time,the experiment results are compared with the actual vehicle test data of the same model equipped with different drive control strategies to verify the feasibility and correctness of the established drive control strategy.The research content of this article mainly includes the following parts:(1)The development status and trend of pure electric buses were analyzed,and the current research and application of vehicle controllers and drive control strategies at home and abroad were summarized.Then,the purpose and significance of research in this paper were proposed.(2)The advantages and disadvantages of structure and drive layout of pure electric buses were analyzed.The development status of the three key technologies related to battery,motor and electronic control was analyzed and studied as the theoretical basis for the construction of the vehicle model and the control strategy model in this paper.(3)Using the theoretical method of hierarchical modeling and applying the AVL Cruise software technology,the mechanical joint,electrical connection and CAN bus signal connection of each component of the JMV6702 BEV pure electric bus were carried out.The relevant data of actual vehicle were input to complete the construction of a relative accurate vehicle simulation model.(4)Comprehensively considering the signals such as vehicle speed,acceleration,and gear,etc.,the vehicle driving mode was divided into starting mode,economic mode,power mode and braking mode.The distribution of motor output torque in each mode was analyzed in detail.Using Matlab/Simulink software technology,a three-layer drive control strategy model that satisfies all driving conditions of the vehicle was built.(5)The dynamic and economic simulations of the drive control strategy model developed in this paper were carried out in a joint simulation experiment.In the actual vehicle experiment with the same model equipped with different control strategies,the controller program flashing and real vehicle data collection were completed.(6)The results of simulation experiment and real vehicle experiment were compared and analyzed,and the correctness and feasibility were verified.The research results show that the drive control strategy formulated in this paper can effectively improve the economy of the vehicle on the basis of guaranteeing the power performance of the vehicle.The drive control strategy has a certain degree of advancement,and the research method can provide a reference for the research of the vehicle drive control strategy.