Research On The Power System’s Parameters Matching And Control Strategy Of The Hydraulic Excavator

Excavator is playing an important role in the construction of modernization.However, its high fuel rate and bad discharge performance make the use-cost of theexactor higher and higher as the deterioration of the environment and the rising of theinternational oil prices.Almost all the exhaust emission, noise emission and most of the energy consumptionconcentrate in the excavator’s power system, so it is important to have a research on thepower system’s structure, parameters matching and control strategy. The research basedon the excavator’s working cycle.The parallel hybrid structure was settled based on the published papers and theworking cycle: an ISG (Integrated Starter Generator) motor assists the engine to drive thehydraulic pumps; a swing motor drives the slewing mechanism, at the same time, itrecovers the slewing mechanism’s braking energy to regenerate the super-capacitor. Thepower system’s simulation model was built on the AMESim software after the structureand components are settled. The model’s inputs are the bucket’s forces in the heavy-loadcycle.To the further optimization of the excavator’s fuel consumption characteristic thispaper matches the parameters of the parallel power system’s components. The matchingcan make sure that every components work in the high efficiency area, so the wholepower system can work efficiently. The parameters include the rated power, the maximumpower and the maximum torque of the engine, ISG motor and the swing motor. Thesuper-capacitor’s energy and power capacity are settled according to the charging anddischarging parameters in a working cycle.The design of the energy management strategy is the most important task in thepaper, also it is one of the technical difficulties. The paper proposes two control strategiesfor the power system: the minimum-assistant strategy and the energy balance strategy according to parallel system’s working characteristics. Then the control strategies aretransformed into the Matlab program which can simulate with the AMESim modelsmoothly. The simulation results show that, with the parallel hybrid structure and theminimum assistant control strategy the excavator’s fuel consumption reduces declined alot.Considering of the shortage of the simulation, the paper also analysis theexperimental data of the hybrid prototype. The results show the lower energyconsumption advantages of the hybrid system used on the excavator. At last, the paperalso proposes some problems that need to be further researched.