Assessment of generator impact on system power transfer capability using modal participation factors

Open access permits all generators to transmit active power into a system. Due to differences in location, output and other factors, however, some generators need more reactive power support than others. Each generator therefore consumes a different amount of reactive power capability of the system. It is very important to develop a quantitative index that can measure the reactive service needs of various generators. Potential applications for such an index include a fair compensation scheme for the procurement of reactive support services from generators, and a market signal for system security oriented generator dispatch. A modal analysis based generator participation factor is proposed to solve the problem. The theory of generator participation factor is presented. A five-bus system demonstrates the concepts and applications. Further case studies are performed using a real-life large-scale power system. Margin sensitivity studies are conducted to confirm the validity of the proposed index.