Evaluation of effectiveness of second-order modal interaction in design procedure of synchronous machines controllers

Abstract

Summary Conventional power system stabilizer (PSS) design may fail in preserving under stress system stability; therefore, PSS redesign using a linearized system stability index (SI) is often prescribed. In this paper, an efficient and more robust algorithm with new ideas is proposed where a twin of SI and a new nonlinearity index form the design objective, a nonlinear participation factor identifies the most involved generators which then both exciters and PSSs of them are tuned. The new design while reduces the adverse effect of modal interaction, significantly improves the dynamic stability with respect to SI design. The method is applied to 2 test systems, and it is shown that the SINI design secures stability in cases that SI design fails. The efficiency and validity of the method are confirmed by comparing the results using both DIgSILENT and MATLAB software.