Research And Development Of New Hybrid Electric Bus Control System

In order to improve the fuel economy of hybrid intercity buses and solve the problem of power interruption during shifting,in this paper we study energy management strategy and transmission control system based on a new plug-in hybrid electric system.The device consists of a main gear-box and an auxiliary gear-box.The new hybrid device can achieve eleven gears.We combine charge depleting-charge sustaining control strategy and equivalent consumption minimization strategy to establish a new management control strategy.Then using genetic algorithm optimizes the motor output torque and shifting gear to achieve real-time control.The output torque of the engine and the motor can be directly interpolated according to the required speed and torque of the hybrid power system.In the ADVISOR software,the parallel motor assisted control strategy is used for simulation,and the dynamic programming algorithm is used to globally optimize the simulation results.In this way,we test the improvement of fuel economy for the energy management strategy which we have proposed.The simulation results show that compared to the traditional vehicle,the fuel economy of the vehicle using the parallel motor assisted control strategy can be improved by 16.61% under the modified C-WTVC conditions.The proposed new management control strategy can save fuel consumption by about 6.8% and 6.4% respectively in CD mode and CS mode,compared to the parallel motor assisted control strategy.The control strategy based on dynamic programming algorithm can reduce 7.2% and 7.48% respectively,which also proves that the management control strategy proposed in this paper has greatly improved the fuel economy of the new hybrid electric system.In the Simulink/Stateflow software,the model of the hybrid electric system and the shifting control strategy are established,and the C code is generated.In order to verify the shifting control strategy,we design the test cases,including starting test,braking test,driving reverse gear test,upshifting and downshifting test.The simulation results show that the new hybrid electric system can realize shifting without power interruption,and the shifting control strategy basically meets the actual requirements.