Research On Energy Management Strategy For Composite Power Supply Of Pure Electric Wheel Loader

The key technology in designing a purely electric wheel loader is that the energy source of the loader can meet its complex load operation requirements.If a single power battery is used for power supply,the loader's operation requirements cannot be perfectly solved.Therefore,this paper uses a supercapacitor as an auxiliary power source and a power battery and a DC/DC bidirectional converter to form a composite power system to power the loader.Through the role of the ultracapacitor “cutting peaks and filling valleys”,buffer battery work load and battery efficiency are improved.,to extend battery life,energy-saving emission reduction purposes.Based on the research of new energy engineering machinery at home and abroad,this paper studies the modeling and simulation of pure electric wheel loader and the energy management strategy of composite power system.The main research contents of this paper are as follows:1.Firstly,analyze the basic working principle and load condition of wheel loader,and combine the structural characteristics,working mode and working principle of composite power supply system to carry out research and analysis.The composite power system with super capacitor as auxiliary power supply can meet the loading requirements.The power requirements of the engine cycle operation,ease the output of the power battery;2.Match the parameters of the motor of the loader and the composite power system,and establish a model of the wheel loader and a composite power supply model according to the relevant parameters.According to the load characteristics of the loader,the logic threshold control strategy and the fuzzy control strategy are formulated.Through the simulation operation,both control strategies can meet the V-type cycle loader requirements of the wheel loader.3.Comparison of single-supply system and composite power system,fuzzy control and logic threshold control strategy simulation results,the results show that the composite power supply is better than a single power supply in terms of energy-saving emission reduction and the reduction of battery losses,fuzzy control strategy is superior to the logic threshold Control Strategy.