Identification Index and Method of Serious Faults and Weak Links in Power System Transient Power Angle Stability

At present, the research on power angle stability of power system has a deep foundation, but most of the methods are based on the analysis of the whole system. The calculation scale is large and the formulas are complex. When the power system is developed immaturely and in an unbalanced way, there are always some weak links. After some faults occur, the weak links may exceed the stability limit and cause instability. The components resulting in the system instability may often be individual, local or regional rather than global. Finding out the critical elements is of great significance for power system analysis, prevention and control. The identification of the critical lines in complex power systems usually needs a complex method, and it is difficult to consider the influence of failures. This paper puts forward the line transient power angle stability index of a complex system which can consider the impact of failures. The method is simple and can obtain the transient power angle stability index matrix of different lines of a power system after different failures only based on the power flow data and simple matrix operations. Through the index the most serious failures and the most fragile lines of the system can be obtained and sorted in order. The proposed index can be directly used to guide the transient power angle stability analysis of power system. A test case is used to testify the application effect of the index in this paper.