基于电液储能调控的多执行器载荷差异均衡系统特性研究

Research on Characteristics of Multi-actuator Load Difference Equalization System Based on Electro-hydraulic Energy Storage and Regulation

工程机械普遍采用集中动力源供能的液压多执行器技术,输出力大、功率密度高,但存在能量利用率低的致命不足。尤其对于执行器复合动作,载荷差异造成的过大节流损失,至今难以找到有效的解决方案。为此,提出多执器载荷差异电液储能均衡系统,采用电液复合储能调控原理对执行器非驱动腔压力进行调控,使各执行器驱动腔压力相等,在同一套硬件基础上,有效降低载荷差异造成的节流损失,同时高效回收了执行机构重力势能。首先对所提系统单执行器的速度和压力控制特性进行试验研究,在此基础上以液压挖掘机为应用对象,对所提系统多执行器复合动作特性进行研究。仿真和试验结果表明,系统具有良好的轨迹跟踪性能和压力控制特性。并且在挖掘机动臂和铲斗复合动作工况下,与电液流量匹配系统相比,所提系统的节流损失降低了75%,能耗降低了12.7%,系统能量回收效率为30.3%,并提升了多执行器复合动作的协调性。新的节能方案同样适用于其他多执行器复合作业的工程机械。

Hydraulic multi-actuator technology powered by a centralized energy source is widely adopted in engineering machineries,with the advantages of large output force and high power density.But the fatal drawback of this method is the low energy utilization efficiency.Especially for the compound action of the multiple actuators,it is difficult to find an effective solution to the excessive throttling losses caused by load difference.Therefore,a load difference equalization system through electro-hydraulic energy storage is proposed.The principle of the electro-hydraulic composite energy storage and regulation is used to control the non-driving chamber pressure of the actuators,so that the driving chamber pressure of each actuator remains equal.On the basis of the same set of hardware,the throttling losses caused by load difference are effectively reduced,and the gravitational potential energy of the working device is efficiently recovered.Firstly,the velocity and pressure control characteristics of the single actuator are tested.On this basis,the compound action characteristic of the multiple actuators of the proposed system is studied with the hydraulic excavator as the application object.Simulation and experimental results show that the proposed system has good trajectory tracking performance and pressure control characteristics.Additionally,compared with the electro-hydraulic flow matching system,the throttling losses and energy consumption of the proposed system are reduced by 75%and 12.7%respectively under the combined action of the boom and bucket.The energy recovery efficiency of the system is 30.3%.Meanwhile,the coordination of the multi-actuator compound operation is improved as well.The novel energy-saving scheme is also applicable to other engineering machinery with multiple actuators.