Research On Energy Efficiency Characteristics Of Pure Electric Drive Hydraulic Excavator Based On Variable Speed

As an important engineering machinery, hydraulic excavators are widelyused in building construction, bridge construction, road construction and otherkinds of construction sites. But because of the bad work environment, big loadfluctuation and other factors, hydraulic excavators have high fuel consumption,serious emissions and other problems, under the background of severeinternational energy crisis, the energy saving property gain more and moreattention. The power sources of hydraulic excavators based on existingtechnology are engine, having large noise, serious pollution, and are not suitablefor city, hospital, school, and some relatively closed place’s work. Electrichydraulic excavator arises at the historic moment, and becomes a new researchdirection of the hydraulic excavator. So this article mainly discusses the energyconsumption characteristics of electric hydraulic excavator based on theco-simulation and experiment of hydraulic excavator.This paper first introduces the structure composition and working principleof ordinary hydraulic excavator, on the basis puts forward the overall scheme ofelectric hydraulic excavator, and study the factors that influence the efficiency of hydraulic pump and frequency conversion motor, puts forward compoundcontrol strategy of the system with variable displacement and variable speed.The control strategy is based on the variable displacement control of LUDVsystem, and the displacement of the pump is the control target of variable speed,in order to achieve the purpose of reducing the energy consumption of the wholemachine.The structure and working principle of excavator hydraulic system arestudied in detail and the LUDV system simulation model is established bySimulationX. This paper introduces the structure of excavator working device,and a three-dimensional model of excavator are established by Pro/E software,and import the three-dimensional model into SimulationX software to build thesimulation model of the work device. The simulation model of working deviceand hydraulic system is verified by experiment. The working principle of theinverter and motor are studied, the simulation models of inverter and motor areset up by SimulationX software, the accuracy of the model is verified byexperiment.Based on the simulation model of the parts and digging resistance, theco-simulation models of ordinary hydraulic excavator and electric hydraulicexcavator are established. In view of the excavator working process, the energyconsumption characteristics of two kinds of hydraulic excavator is studied. Theresults show that compared with the ordinary hydraulic excavator, electrichydraulic excavator save energy consumption costs by more than30%, effectively reduce the energy consumption costs.In order to further improve the energy saving property of electric hydraulicexcavator, in view of the excavator working process, the energy consumptioncharacteristics of electric hydraulic excavator is studied under different "pumpdisplacement target value" and under different speed range. The simulationresults show that when the speed of the motor is set for1200-1500RPM, and"pump displacement target value" is set to0.9, power consumption of electrichydraulic excavator is the least. The electric hydraulic excavator design researchhas certain guiding significance.