Study On Energy Management Strategy And Mode Transition Control For A Dual Planetary Hybrid Electric Bus

With the continuous improvement of China's industrial manufacturing technology,hybrid highway buses have been gradually running to the market and received positive feedback.The value advantages such as large capacity,low fuel consumption and maintenance along with the basic advantages such as high dynamics,low fuel economy and security of hybrid highway bus make it can fully meet the user needs of the bus market,and so as to create an extremely important part of the green travel process.In this paper,a dual planetary hybrid electric bus is taken as the research object in combination with a enterprise cooperation project,and the relevant work on the energy management strategy and mode transition control is carried out.First of all,in order to design the configuration of the dual planetary hybrid electric bus,a set of parameter matching method which considers multiple factors is proposed.According to power demand for maximum speed,acceleration time and maximum climbing performance as well as energy demand for regenerative braking in typical driving conditions,based on the principle of engine control strategy and transmission system efficiency,the parameters of the engine,motor,battery and other components like planetary platoon feature parameters,main reduction ratio and wheel rolling radius have been matched.The model is build in the co-simulation platform of Cruise and Matlab/Simulink software and the results show that both the dynamic performance and fuel economy are improved.Secondary,consider the influence of transmission efficiency on the system,the genetic algorithm is used to optimize the separation factor that affects the overall efficiency of the power system under different conditions.So an instantaneous optimal energy management strategy based on genetic algorithm can be proposed to control each component and improve the dynamic performance of the system.Finally,in order to explore the mechanism of impact degree during the mode switching of highway bus,different mode switching coordination control strategies are formulated for different typical working conditions.When the system is switched from the pure electric mode to the hybrid mode,a power source trajectory optimization and coordinated control method is adopted.When the system is switched from hybrid hybrid mode to engine direct drive mode,the model predictive control of locking clutch engagement process is studied.The proposed coordinated control strategy algorithm is verified in the co-simulation platform of Cruise and Matlab/Simulink software and the results show that the impact of the system is reduced and the ride comfort of the vehicle is improved.In summary,the overall research process of parameter matching,energy management strategy and mode rransition control for a dual planetary hybrid dlectric bus in this paper is relatively complete,which has laid a good foundation for the market launch of real vehicles and has certain academic reference value for the current research status.