Abstract

In this paper an attempt has been made to propose a new technique for selection of optimum site of a power system stabilizer (PSS) to mitigate the small-signal stability problem in a multimachine power system. Study reveals that the PSS displaces the swing mode from its critical position to a more desirable position changing the response of the excitation system. Based on the change of the exciter transfer function with respect to the PSS transfer function, an optimum PSS location index (OPLI) has been introduced and used to identify the best location of the PSS in a multimachine system. The analysis of the effect of load on eigenvalues confirms that the prediction of best location of PSS by OPLI method is more effective in enhancing the small-signal stability of the system.

Key words: Critical swing mode, optimum PSS location index, sensitivity of PSS effect, small signal stability.