Coordination Control between PSS and SVC Based on Fuzzy-Satisfactory Degree and MOEA

Power system dynamic stability includes two problems: power angle stability and voltage stability. For the former, the best way is to install power system stabilizer (PSS) on the key generator groups, and for the latter, however, Flexible AC transmission systems (FACTS) devices such as static var compensator (SVC), static compensator (STATCOM) and so on are the popular methods. PSS can effectively enhances the damp of the system, so is helpful for improving the stability of power angle, but it has little affects on the voltage stability. SVC not only improves the voltage stability but also reinforces the damp of the system if additional control is suitable. A multi-aim optimal designing method which is based on fuzzy-satisfactory degree theory is presented to solve the problem of cooperation control of PSS and SVC. Simulation results show that, used the solution presented in the paper, the stability of power angle and voltage can be effectively enhanced.