机电液系统多参量耦合机理及动能刚度分析方法

Multi-variable coupled mechanism and kinetic energy stiffness analysis method for a mechanical-electrical hydraulic system

针对机电液系统运行过程中对性能可靠性分析及其评价方法的迫切需求,分析了机电液系统多能域参量在负载工况和动力源联合作用下的耦合机理,在建立机、电、液各子系统内部耦合效应作用链的基础上,提出机电液系统动能刚度分析方法,揭示了多源变参量作用下系统动能刚度的变化规律。以典型机电液系统——变转速泵控马达系统为研究对象,建立了其数学模型,分析了系统多能域参量对其运行状态的影响机制,阐明了动能刚度的物理意义以及对机电液系统运行性能评价的重要意义;通过机电液系统多源信号的变化率特征计算运行过程中的动能刚度角,并以此衡量动能刚度大小。在此基础上,研究动能刚度的变化规律。理论分析与实验验证均表明:动能刚度是机电液系统内部多参量的耦合效应,随多能量域参量变化;根据激励源不同,动能刚度分为正向刚度与逆向刚度,可以分别作为系统抵抗动力源变化和负载工况扰动性能的评价指标参数;在线检测并控制系统动能刚度的"刚-柔"匹配过程可以有效保障机电液系统运行性能的可靠性。

Aiming at the urgent demand of performance reliability analysis and evaluation method for a mechanicalelectrical hydraulic system,the coupled mechanism of multi-energy-domain parameters under the combined action of load condition and power source was analyzed. The function-effect chain among mechanical, electrical and hydraulic subsystems was established. Based on the above theoretical basis,the analysis method of kinetic energy stiffness（ KES）suitable for the mechanical-electrical hydraulic system was proposed. The changing law of the system’s KES under the action of multi-source parameters was revealed. Taking a typical mechanical-electrical hydraulic system-variable speed pump controlled motor system as the study object,its mathematical model was built. The effect mechanism of multienergy-domain parameters on the system’s running states was analyzed. The physical meaning of KES and its important meaning to evaluation of the mechanical-electrical hydraulic system’s running states were presented. In order to measure KES,the magnitude of KES was calculated with the change rate of multi-source signals of the system. The theoretical analysis and test results indicated that KES is the inner multi-variable coupled effect of the mechanical-electrical hydraulic system,it varies with multi-energy-domain parameters; according to different excitation sources,KES can be divided into forward KES and reversed KES,they can be the evaluation indexes for the system’s anti-power source varying and antiload disturbance performances,respectively; on-line detecting and controlling the ＂rigid-flexible＂matching process of the system’s KES can effectively safeguard the running performance reliability of the mechanical-electrical hydraulic system.