Generator ranking using modal analysis

As is well known, generators are important reactive support devices in power systems. Due to difference in location, active output and other factors, however, specific generators are of differing importance to the system. There is a need to develop an index to measure the relative importance of the generators. Modal analysis is extended to include entries for generators. A generator ranking method is then developed based on the participation factors related to the critical mode in the vicinity of the point of voltage collapse. Simulation and verification studies are conducted on different scale systems including a 1000-bus real-fife system. The results show the validity of the proposed method and that the participation factors are a comprehensive index taking into account all related factors. An example is also provided to illustrate the application of this ranking index.