在线监测电机功率状态的图形识别方法

A Monitoring Method for Power Condition of AC Motors via Graphic Recognition

以交流电机及其拖动系统运行状态在线识别以及功率优化控制为研究目标,基于李萨如方法将交流电机定子三相电流和电压提供的幅值、相位、相间和相序信息融合成李萨如动态图形,由数学分析论证推导出李萨如图形面积、外接矩形面积、摆动角度等特征量与电机功率之间的函数关系,通过计算李萨如图特征量生成表示电机功率变化状态的功率圆图形,实现了电机功率状态、拖动系统运行工况在线监测的图形识别技术。试验结果表明:李萨如图形及生成的功率圆图形可以在线表示电机的有功、无功和视在功率的动态变化过程以及设备负荷与电机的功率匹配过程;通过李萨如图形摆动角度可以识别电机加载、减载、冲击、过载保护以及电动和发电等典型工况。

In order to realize on-line recognition and power optimization control of the AC motor driving system, amplitude, phase, and phase sequence of three phase current and voltage were synthesized into Lissajous figure by Lissajous method. Functional relationships between motor power and the graphic features （including Lissajous figure area, boundary rectangle, swing angle） were deduced by mathematical analysis. The power circle graph which can express motor power various state was obtained by calculating graphic feature quantifies of Lissajous figure. Figure recognition technology of motor power state and running condition of driving system was realized. The experimental results show that, Lissajous figure and power circle graph can on-line illustrate power matching procedure of load and motor, and dynamic procedure of motor active power, reactive power, and apparent power. From Lissajous figure swing angle, the typical running conditions recognition of AC motor, such as loading, unloading, impacting, overloading protection, and power drive and power generation can be accomplished.