| With the research and development of hybrid power system,with the development of battery technology and control methods,the hybrid electric power system has made great progress in the automotive industry.However,vehicle operation and hydraulic excavator can be quite different: long term car running in good condition of the highway pavement,the smooth running speed;the hydraulic excavator with little displacement,and the single cycle memory in obvious power fluctuation of excavator.Because of the high power density and low price,the accumulator can reduce the power of the engine and improve the fuel economy.In this paper,we study the power matching of the oil hydraulic hybrid power system:(1)The development of the traditional hydraulic excavator,analyzes the energy loss in the excavator working process,along with the development of hydraulic technology maturity and engine technology,pointed out to rely on a single or dynamic optimization system of hydraulic system,saving space is limited,cannot be applied to the new generation of excavator.Then,analysis of the characteristics of the hybrid system and hydraulic hybrid system,which has high energy density,low price of the accumulator and the pump / motor is matched with the hydraulic hybrid system,as a new type of hydraulic excavator power system has great potential.Thus,the research significance and the research contents of this paper are presented.(2)Taking the LS and LUDV system as an example,the working characteristics of the hydraulic system of the traditional hydraulic excavator are analyzed.Based on the analysis of its working principle,the Simulation X model is built by 6T excavator,and the accuracy of the model is verified by simulation analysis.The mechanical structure of the excavator is modeled by Pro/E software,and the motion unit is set up with Simulation X.Finally,the working condition of the hydraulic excavator is analyzed,and the typical excavation condition is determined.The simulation is carried out,and the simulation results are compared with the test data.(3)Through the series type of parallel type,and studied the hybrid three hybrid scheme,and from the energy saving effect and modification cost are analyzed,and ultimately determine the parallel hydraulic hybrid scheme as the power system of 6t excavator.Then,the two quadrant pump / motor matched with the two-way pump is designed as the auxiliary power unit.On this basis,the Simulation X model of engine,accumulator and pump / motor is established.Finally,the parameters of the hybrid engine,the accumulator and the pump / motor are matched.Complete the whole model of hybrid excavator.(4)By analyzing the working conditions of the excavator engine,the control strategy of the hybrid excavator is designed based on the load balance.According to the traditional hydraulic excavator in the mining condition when the average load power,setting the output power of the diesel engine;when the load fluctuation,through the two components to absorb and release power;finally realize the stable output power of the diesel engine in the vicinity of average load power and pressure through feedforward control strategy,in order to optimize the engine installed power is selected diesel fuel economy optimal machine,to achieve energy saving goals.According to this method,the simulation experiment of the oil hydraulic hybrid excavator is carried out to verify the feasibility of the control strategy.(5)At the end of this paper,the main work in the research process,the innovation and shortcomings of this paper are summarized,and the key points that should be paid attention to in the next work are stated... |
PDF Full Text Request