Dynamic coordinated control of power-split hybrid electric vehicle based on fixed-time adding a power integrator

In order to improve the transient mode switching quality from the motor driving to the hybrid driving stage of a power split hybrid electric vehicle (PS-HEV), a novel finite-time dynamic coordinated control strategy (DCCS) that combines adding a power integrator (AAPI) and fixed-time control theory is proposed. Firstly, dynamic models of the PS-HEV at different stages are established using the lever analogy. Based on the transient mode switching analysis, the AAPI controller is constructed for the engine starting and clutch slipping stage. The power integral term in AAPI can improve the controller robustness. Then, the fixed-time control theory is introduced into the design of the AAPI, and fixed-time adding a power integrator (FTAAPI) control strategy is further proposed to improve the convergence performance of the engine speed and clutch speed difference. Finally, simulation and hardware-in-the-loop (HIL) experiments are conducted. Research results show that the proposed FTAAPIC reduces the speed difference between both sides of the clutch with faster convergence rate and lower steadystate error. Compared with the traditional sliding mode control and AAPI strategy, the mode switching quality of the PS-HEV with the proposed FTAAPI strategy is greatly improved in scenarios considering external disturbances.