摘要
定性地分析电力系统正常运行状态和故障后的稳态量时,电压相量图法是十分有用的工具。电压相量图法是运用电工中基本的定理或定律及几何基础知识,在电压平面上绘制出故障点的电压、电流相量,保护安装处的电压、电流相量及其组合相量(补偿电压等),甚至系统中任意点的电压相量。电压相量图用来分析距离保护的动作行为时,其物理意义非常清楚,然而,人们习惯在阻抗平面看测量阻抗的变化轨迹和阻抗保护的动作边界,而应用复数平面反演方法,即可实现电压平面与阻抗平面的变换。得到保护安装处的测量阻抗轨迹和阻抗保护的动作边界。在分析时,经常假设一些参量为定量(如等有功、等电压等)、一些参量为变量(如振荡中的功角d、接地电阻等),观察相关电压相量的变化轨迹,建立电压平面与阻抗平面的几何关系,以利采用电压相量图法所得的经典结论,对阻抗保护的研发和运行分析起到直观、快捷的指导作用。
The voltage vector diagram is a very useful method that can make a qualitative analysis of the steady values of power system in normal and fault conditions. Appling the basic electrical theorems and geometry knowledge, the voltage and current vectors and those combinations, as example, the compensated voltage , can be drawn, at the fault point, at the point where the protection installed and even any random points in the system in the voltage vector plane. This diagram has very clear physics meaning, which exerts the voltage vector diagram to analyze the impedance protection. But it is usually used to analyze the trace of the measured impedance and the operation boundary of the impedance protection in the impedance plane. A new method is put forward in this paper, by which we can flexibly realize the transform from the voltage plane to the impedance plane. Therefore we can easily get the track the measured impedance at which the protection installed and the operation boundary of the impedance relay. Furthermore if some parameters are supposed constant , such as equal active power, equal voltage and so on, and some others variable, for example the swing, the grounding resistance etc, the geometry relation can be built up between the voltage plane and the impedance plane by the means of observing the movement of the voltage vector. And then the classical conclusion drawn from the voltage vector diagram can serve as a straight and convenient guide to the research and operation analysis of the impedance protection.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2004年第1期40-43,共4页
Proceedings of the CSEE
关键词
电力系统
定性地分析
阻抗保护分析
电压平面
阻抗平面
电压相量图法
Power system
Voltage vector diagram
Measure impedance
Impedance protection
Voltage plane
Impedance plane
Transform
