中文摘要：

以液压系统运行状态在线监测、故障诊断以及功率优化控制为研究目标,提出将电动机三相交流电源的电压、电流信号用李萨如图产生单相及三相信息融合方法。利用机电动力学建立交流电动机驱动液压系统的动态功率平衡方程,分析电、机、液能量的转换和耦合过程,在此基础上提出用三相电气参量提供的幅值、相位、相间和相序信息绘制单相和三相李萨如动态图形,由数学分析推导出李萨如图形面积、外接矩形、摆动角度等特征量与交流电功率之间的函数关系,通过计算李萨如图特征量的变化实现对液压系统运行状态、运行工况以及功率匹配情况进行在线监测,形成基于电参量信息融合的液压系统运行状态识别技术。研究结果表明,单相李萨如图形面积可线性表示液压系统负载功率的在线状态,其外接矩形面积表示电源负荷状态,由此构成的功率圆可以在线监测电动机与液压系统负载工况的功率匹配过程;通过李萨如图形特征可以识别液压系统加载、减载、冲击、过载、溢流以及储能等典型工况;根据本方法形成的三相李萨如图还可对液压系统的电动机、机械和液压故障进行分类判别。

英文摘要：

A dynamic power balance equation and an electrical parameters information fusion method are presented to study on state recognition and power control technique of the hydraulic system driven by alternating current（AC） motor.To analyse the electrical,mechanical,hydraulical energy conversion and coupling process,the power balance equation of the hydraulic system is established using electromechanical dynamics.Based on the analysis result of equation,the single-phase and three-phase lissajous＇ graph are drawn dynamically by means of the multi-source information such as phase,amplitude and phase sequence provided by the three-phase currents and voltages.The functional relations between the graphics features and dynamic powers of the AC motor are put forward,and then the functional relations are transferred into the power circle function for graphical analysis of the dynamic power.The results of the prototype experiments and on-site tests show that the typical running conditions such as loading,unloading,impact,overflow,energy-storage and so on,can be recognized by the calculations of the graphics features.A state recognition technique via information fusion is built finally.The research leads to the conclusion that the closed area of planar lissajous＇ graph shows the real power of AC motor,which indicates the changing of load and lossed power,and the out-rectangle area represents the apparent power,the power circle can on-line monitor the matching process of the motor power with the typical running conditions,the swing angle of the graph provides some characteristic information relevant to the motor running status.In additional,three-phase lissajous＇ graph is used not only to identify the running condition,but to classify the fault of the motor and hydraulic system.