为使液压挖掘机在负载多变条件下节能降耗,需使发动机与变量泵系统实现功率匹配。建立发动机外部特性与变量泵调节装置的数学模型,并提出动力系统功率匹配节能控制策略以及实现该策略的模糊控制算法,得到节能控制系统的理论模型。通过采...为使液压挖掘机在负载多变条件下节能降耗,需使发动机与变量泵系统实现功率匹配。建立发动机外部特性与变量泵调节装置的数学模型,并提出动力系统功率匹配节能控制策略以及实现该策略的模糊控制算法,得到节能控制系统的理论模型。通过采用Matlab/Simulink建立发动机与变量泵功率匹配节能控制系统仿真模型,模拟挖掘机在不同负载下节能控制系统的运行状态。将控制算法写入主控制器的电子控制单元(Electronic control unit,ECU),在试验样机上进行试验。模拟仿真和试验结果表明,采用该节能控制算法后,发动机转速能稳定在目标转速附近,并降低燃油消耗率,达到节能效果。展开更多
Though the traditional energy regeneration system（ERS） which used a hydraulic motor and a generator in hybrid excavators can regenerate part of the energy, the power of the motor and the generator should be larger a...Though the traditional energy regeneration system（ERS） which used a hydraulic motor and a generator in hybrid excavators can regenerate part of the energy, the power of the motor and the generator should be larger and the time for regenerating energy is so short. At first, the structure of new ERS that combines the advantages of an electric and hydraulic accumulator is analyzed. The energy can be converted into both the electric energy and the hydraulic energy at the lowering of the boom and the generator can still works when the boom stops going down. Then, a method how to set the working pressure of the hydraulic accumulator is proposed. To avoid the excess loss, extra noise and shock pressure, a two-level pressure threshold method that the generator starts to work at the rising edge of the high pressure threshold and stops working at the falling edge of the low pressure threshold is presented to characterize the working mode of the generator. The control strategies on how to control the boom velocity at the lowering of the boom and how to improve the recovery efficiency when the boom stops going down are presented. The test bench of hybrid excavator with ERS is constructed, with which the studies on the influences of ERS on energy conversion efficiency and control performance are carried out. Experimental results show that the proposed ERS features better speed control performance of the boom than traditional ERS. It is also observed that an estimated 45% of the total potential energy could be regenerated at the lowering of the boom in the proposed ERS, and the power level of the generator and the hydraulic motor could be reduced by 60%. Hence, the proposed ERS has obvious advantages over the traditional ERS on the improvement of energy regeneration time, energy efficiency, control performance and economy.展开更多
文摘为使液压挖掘机在负载多变条件下节能降耗,需使发动机与变量泵系统实现功率匹配。建立发动机外部特性与变量泵调节装置的数学模型,并提出动力系统功率匹配节能控制策略以及实现该策略的模糊控制算法,得到节能控制系统的理论模型。通过采用Matlab/Simulink建立发动机与变量泵功率匹配节能控制系统仿真模型,模拟挖掘机在不同负载下节能控制系统的运行状态。将控制算法写入主控制器的电子控制单元(Electronic control unit,ECU),在试验样机上进行试验。模拟仿真和试验结果表明,采用该节能控制算法后,发动机转速能稳定在目标转速附近,并降低燃油消耗率,达到节能效果。
基金supported by National Natural Science Foundation of China(Grant No. 50875233)National Hi-tech Research and Development Program of China(863 Program, Grant No. 2010AA044401)+3 种基金Open Fund of the State Key Lab of Flow Power Transmission and Control(Grant No. GZKF-201111)National Youth Science Foundofion of China(Grant No. 51205140)Fundamental Research Funds for the Central University of China(Grant No. JB-ZR1208)Scientific Research Funds of Huaqiao University, China(Grant No. 11BS409)
文摘Though the traditional energy regeneration system（ERS） which used a hydraulic motor and a generator in hybrid excavators can regenerate part of the energy, the power of the motor and the generator should be larger and the time for regenerating energy is so short. At first, the structure of new ERS that combines the advantages of an electric and hydraulic accumulator is analyzed. The energy can be converted into both the electric energy and the hydraulic energy at the lowering of the boom and the generator can still works when the boom stops going down. Then, a method how to set the working pressure of the hydraulic accumulator is proposed. To avoid the excess loss, extra noise and shock pressure, a two-level pressure threshold method that the generator starts to work at the rising edge of the high pressure threshold and stops working at the falling edge of the low pressure threshold is presented to characterize the working mode of the generator. The control strategies on how to control the boom velocity at the lowering of the boom and how to improve the recovery efficiency when the boom stops going down are presented. The test bench of hybrid excavator with ERS is constructed, with which the studies on the influences of ERS on energy conversion efficiency and control performance are carried out. Experimental results show that the proposed ERS features better speed control performance of the boom than traditional ERS. It is also observed that an estimated 45% of the total potential energy could be regenerated at the lowering of the boom in the proposed ERS, and the power level of the generator and the hydraulic motor could be reduced by 60%. Hence, the proposed ERS has obvious advantages over the traditional ERS on the improvement of energy regeneration time, energy efficiency, control performance and economy.
