Study On Static Voltage Stability Control Based On Sensitivity Information

Power utility has becomed the infrastructure of modern society. To keep power system stability and security is very important for human being. In recent years, with the development of high-voltage, long-distance transmission, and power deregulation, more and more uncertainties and insecurities emerge in power system planning and operation. More attention has been paid on various power system stability problems. As an important part, voltage stability and voltage collapse has become a real dangerous limit for power system operation and development nowadays. In this thesis, we mainly focus on seeking effective control method to enhance power system stability and avoid voltage collapse. A voltage stability control method based on sensitivity is presented. Some influence factors to the method such power flow algorithm, branch parameters are also discussed. Main work of this thesis is as following:1. Based on review to previous works, a voltage stability control method based on sensitivity information is presented. Using the result of AC power flow, sensitivity factors between the power flow on branches and node injections are obtained, which can be used to determine the candidates of load shedding and generator tripping. The voltage stability then can be enhanced by adjusting power flow on some critical branches and interfaces. Some influences to the method such as algorithm of AC power flow, parameters of branches are also discussed.2. Comparison between the presented method and control method based on power flow tracing and re-dispatching are performed. Control errors of two methods are also analyzed.3. The presented method is validated in the New England-39 bus system. It reveals that the control method is correct and effective.