Design And Applications Of CAN Network System For Plug-in HEV

With the increasingly serious air pollution in the city,people’s living environment is deteriorating gradually,and it is imperative to reduce the emission of automobile exhaust.Driven by the policy and market,the demand for new energy products is increasing gradually,in which new energy buses as the main products occupy the leading market.Compare with that traditional bus and other new energy systems,the plug-in hybrid pow system bus has the characteristics of both pure electric power and hybrid power in function,has a pure electric operation mode,achieve zero emission,the CAN bus also be used as a hybrid power operation mode,ensures the operation mileage and the power performance,and has flexible charging.Because the new energy bus has high current,high voltage and other electric drive parts,the electromagnetic disturbance is much higher than the traditional bus.Because of its complex system structure,bad electromagnetic environment,and high real-time communication between the parts,the CAN network design and communication quality is particularly important.The main contents of this paper are as follows:(1)In this paper,the plug-in hybrid power system CAN network communication system as the research object,briefly introduces the composition of the control system,according to the system configuration of power control nodes,the characteristics of high demand for real-time communication,design an effective CAN network system architecture,study the CAN network communication protocol setting rules,and complete the communication protocol settings and communication protocol formulation.(2)Aiming at the real-time communication problem in the CAN network design,the communication control principle of the CAN network is analyzed,and the layered network topology design scheme of the CAN bus is studied.The key factors affecting the real-time performance are analyzed and sorted out.The delay optimization measures of the CAN network are analyzed and verified in detail by establishing model simulation calculation,which improves the real-time performance of vehicle can network system communication.(3)Aiming at the electromagnetic compatibility of can network,combining with the design of the CAN network and real vehicle test cases,the paper studies the parts grounding point setting,shielding line and grounding,interference source distribution and reasonable avoidance,the CAN line waveform analysis and so on.Through optimization measures,the electromagnetic compatibility of the CAN network is improved.(4)The topological structure of 18 meter plug-in hybrid electric bus for CAN network system is designed in this paper,and the communication quality is optimized.Through the application test,the results show that the communication quality of the designed the CAN network system is reliable,meets the requirements of the vehicle type,has the characteristics of high real-time performance and high anti-interference ability,improves the quality of can communication,and ensures the anti-interference ability of the system.