Study On Energy Saving Control And Parameter Optimization Of Hybrid System In Hydraulic Excavator

Energy is increasingly shortage, so research on energy saving of hydraulic excavators has great significance because of their large application quantities and high energy consumption.The structure, parameter matching and control strategy are the main factors affecting the efficiency. In the dissertation, after the structure of hybrid systems in this hybrid system is established, the corresponding control strategy is proposed, and then simulate. The parameters matching of the hybrid system and the optimization of energy saving are studied based on the above research.The chapters of the dissertation are summarized as follows.Chapter 1 Introduction. the significance of the research on hydraulic excavators energy saving is discussed. Research status on the domestic and international energy saving of hydraulic excavator and Hybrid technology is introduced. Combined with the characteristics of hydraulic excavators, the application of hybrid technology in the hydraulic excavators is proposed. And this chapter analyzes the investigative profile of the current hybrid hydraulic excavator. Finally, the main research contents of the dissertation are proposed.Chapter 2 Study on hybrid system in hydraulic excavators. this chapter analyzes the principle of implementation and drive mechanism and the working process of hydraulic excavator. And introduce the working characteristics of the load combined with the actual operating conditions.Parallel hybrid system is finally chosen by comparing the merits and demerits of parallel and series hybrid system. And the main components of hybrid system including engine, electric motor and hydraulic pump are analyzed specifically. And compares the merits and demerits of different accumulators.Chapter 3 Control strategy of hybrid system in hydraulic excavators. the main research are the control strategies of the hybrid system. Firstly, this chapter introduces the current control strategies of vehicle hybrid systems and hydraulic excavator hybrid system. Referring to the control strategies of vehicle hybrid system and combined with the specific characteristics of hydraulic excavators, Instantaneous Equivalent Consumption is introduced to the hydraulic excavators. According to the state of electrical energy storage and consumption, defines and analyzes the future consumption of energy and the future compensation of energy, the maintenance strategy of SOC is proposed. And this chapter finally establishes the objective function of Instantaneous Equivalent Consumption.Chapter 4 Simulation of hybrid system in hydraulic excavators This chapter establishes the parallel hybrid system simulation model. Comparison the energy saving effect of rule-based logic threshold control strategy and the Instantaneous Equivalent Consumption control strategy, Simulation results show that the Instantaneous Equivalent Consumption control strategy is more significant in the fuel efficiency, and more suitable for the actual control.Chapter 5 Parameter matching of hybrid hydraulic in excavator system and study on energy saving potential based on the Instantaneous Optimization. by GA Optimization Toolbox and Genetic Algorithm, the parameters of hybrid system are matched. and the control parameters of the Instantaneous Equivalent Consumption are optimized. Fuel savings increase to 13%.Chapter 6 Summary and outlook. the achievements are summarized, and the further work needing to study is put forward.