Research On Hybrid Excavator Based On Energy-Saving Hydraulic System

Energy saving, environmental protection has been the main objectives pursued by the domestic and international manufacturers of hydraulic excavators. Under this background, a22-ton hydraulic excavators driven by double-pump as the research object is modeled within Simulink and several branch physical simulation toolbox Simscape of MATLAB system. The parallel, series and compound type hybrid hydraulic excavators are simulated and evaluated. Finally, a scheme with a series of energy saving method, such as compound type hybrid, electric motor driving swing, the energy regeneration based on the closed volume control hydraulic system, is presented and synthetically evaluated.The main contents of each chapter are summarized in the following:In Chapter1, the significance of the research on energy saving for hydraulic excavators is discussed, and the current state and development history of the research on energy saving in hydraulic excavators are introduced. Some characteristics and shortcomings of these energy saving methods are analyzed, and the project be determined and the research content in the dissertation are summarized.In Chapter2, the working principle of hydraulic excavators, a standard digging cycle and the characteristics of load be analyzed, a simulation model of a22ton class hydraulic excavator mechanism and the hydraulic system is built up with Simulink and SimMechanics toolboxes of MATLAB system.In Chapter3, based on the built simulation models of hydraulic excavators, the simulation research for a standard digging work was performed and form the simulation result recognize that improve of the hydraulic system is one of main key in the research on energy saving of hydraulic excavators, so the simulation research on design of a new energy saving hydraulic system as one of main project was performed.In Chapter4, for the hybrid hydraulic excavators with the new energy saving hydraulic systems and super capacity, the simulation models was built up and the simulation result was analyzed. According to the analysis result, parallel hybrid mode was chose as hybrid mode of hybrid hydraulic excavators.In Chapter5and Chapter6, based on the current power control strategy and the parameter match method, a kind of power control strategy named the dynamic working point control strategy based on stabilize of rotation velocity of engine and load recognition and a kind of parameter matching method is proposed. Simulation result indicates feasibility of power control strategy and parameter matching method proposed.In Chapter7, for a hybrid of the current22ton "Rakwon" hydraulic excavators, new energy-saving hydraulic system and hybrid structure was proposed, through simulation, it was proved that the design of new energy-saving hydraulic system, hybrid structure, the parameter settings of power components, the control strategy is feasible.