Optimal Control Strategy of Hybrid System in Hydraulic Excavator

Power path and load mode of the traditional hybrid hydraulic excavator is analyzed,and then the high fuel consumption area of the engine is found.An optimal control strategy of adaptively adjusting the dynamic optimal DOH(degree of hybridization) by actively recognizing the load mode is propounded based on parallel hybrid system.Under this optimal control strategy,the dynamic optimal hybridization is divided into four grades and the engine is always made working around the optimal economical area by multi-conditions control and adaptive power match.The fuel consumption and torque models of the engine in hybrid excavator with the optimal control strategy and traditional hybrid vehicle are established and simulated by MATLAB/Simulink.The simulation results indicate that,under this strategy,the fuel consumption is reduced and the energy is saved more efficiently in the hybrid system.