基于向量场正规形方法的功角和电压稳定特征分析

通常意义下的功角稳定性和电压稳定性事实上只反映电力系统稳定性的不同方面,作为一个整体,电力系统稳定性本质上是一个综合问题.文中采用向量场正规形理论,对系统稳定运行点的特性进行研究,发现应用向量场正规形方法得到的高阶解析解包含了电力系统稳定性的更多信息,便于分析和理解系统非线性的本质.用它来研究系统内部模式间的非线性相关作用,可以分析出功角和电压稳定的特征,为分析强非线性下系统的稳定性及非线性特性提供了一条新的有效途径.同时,还用非线性动力学方法分析了系统的稳定运行点和不稳定运行点的特性,并与文中所使用方法的分析结果进行了比较,对一个简化电力系统的分析实例表明,电力系统中的各种稳定模式是相互影响的,系统在稳定边界附近所表现出来的非线性现象和相应的不稳定运行点的特性一致反映了系统所面临的失稳模式.

Normal Forms of Vector Fields Based Analysis of Power System Angle and Voltage Stability Characteristic

The angle stability and voltage stability commonly are considered as the partial stability problem of power system. The stability for a unified system is essentially an integrated problem. By using the theory of normal forms of vector fields, with the auxiliary dynamic system, the characteristics of the power system at the stable operating point are investigated in this paper. The research results show that more dynamic information of the power system can be obtained by the proposed method and the nonlinear characteristics can be identified. Also, it is found that investigating the interaction between the angle and voltage stability modes is helpful to analyze the stability of nonlinear system and the nonlinear characteristic. For verifying the effectiveness of the proposed method, the performance of the unstable operating points and the stable operating points are also analyzed by the nonlinear dynamics theory. Results are satisfactory. Applications in a simple power system show that different modes of the power system do interact each other. When the power system operations are very close to the stable boundary, its nonlinear behaviors and performances of the unstable operation points both show the unstable modes of the system.