Remedial Action Schemes Derived from Dynamic Security Assessment

Electric power is becoming more and more important in the modern world. Since most electric power utilizations should be supplied by the power transmission and distribution system, the security of power system is paid more and more heed to nowadays. All over the world, there are some trends to introduce the deregulated power system into the power system operation, and to increase the stability of electric power supply. As a result, making accurate predictions for the power system operating conditions is an important task for the current power system research. The research mainly interests in checking if the operating conditions are acceptable after contingencies. Dynamic Security Assessment (DSA) is proposed and studied under such context. One tool to implement the DSA is to create the Stability Indices (SI) system. The SI system is used to indicate the operating conditions for the power system. This master thesis project aims to develop the appropriate Remedial Actions Scheme (RAS) by using the SI system. The RAS is used against different instabilities. Firstly, all indices of the SI system are summarized. The summarization is based on theoretical study on to-date DSA researches. The indices of the SI system are able to predict power system operating conditions. They are also able to release the stress of DSA computing, and to reduce misclassification and failed-alarm. The SI system is computed by quantities of state variables from the components of the power system. Secondly, the functionalities of different remedial actions are clarified. Then, those remedial actions are used to develop the RAS. The RAS is developed according to the evaluation by the SI system. Using the SI system, different remedial actions are tested and evaluated. The results of evaluation are used to develop and categorize different RASs against different instabilities. After that, the RASs are analyzed, and qualities of RASs are ranked by the SI. In this way, more suitable RAS against each type of instability is developed. The results show the process of analysis is both fast and accurate. All analysis and evaluations are implemented by simulation software of PSS TMNETOMAC. The thesis has been implemented between cooperation of Royal Institute of Technology (KTH) in Sweden and Energy Sector of Siemens AG in Germany