Excitation systems-performance specification to meet interconnection requirements

The excitation system transient gain has a direct impact on power system small signal transient and dynamic stability. The computer models provided to the customer at the proposal or project stage should reflect the transient gain required to meet the project specification. Settings and models with lower gains may not be adequate to give desired performance. Higher gains, to meet response times, may result in dynamic instability if the system becomes weaker, such as during contingency events. The benefits of power system stabilizer (PSS) control to improve stability margins in these cases are reviewed by the authors in this paper.