Analytical Method for Short-Term Voltage Stability Using the Stability Boundary in the P-V Plane

Short-term voltage stability is one of the issues of concern for power system operations. As dispersed power generation is connected to middle- and low-voltage transmission networks, the development of analytical methods will become more important. This paper describes a stability boundary line in the P-V plane of the load bus for the analysis of short-term voltage stability. By comparing the operating point of the load with the boundary line, we can visually determine the acceleration or deceleration state of the induction motor, thereby clearly explaining the short-term voltage instability phenomena. In addition, the idea of the stability boundary is applied to voltage stability assessment and emergency controls such as reactive power compensation. Numerical simulations are carried out for a single-load infinite-bus system to explain the basic theory of the proposed method and to provide examples of its application.