Abstract:
To solve the problems that single energy system could not give full play to its advantages and could not well satisfy the high density of random load spectrum during the operation of tractor, the composite energy system of electric tractor was designed based on parallel connection of hydrogen fuel cell, power battery and supercapacitor. The hierarchical decoupling control energy management strategy based on Haar wavelet and logical threshold rules was designed to realize the hierarchical decoupling of high frequency signal, sub-high frequency signal and steady state signal, and the power signal was distributed after decoupling. The simulation results show that compared with the power following control strategy and the fuzzy control strategy, the average efficiency of the hydrogen fuel cell based on the layered decoupling control strategy is respectively improved by 2.85% and 1.21%, and the vehicle equivalent hydrogen consumption is respectively reduced by 16.11% and 6.88% in the experimental cycle. The proposed control strategy can improve the vehicle economy on the promise of meeting the power demand of vehicle load, and the fuel cell can output power in efficient and stable working state.