Study On Damping Characteristics Of Close Modes Power System

The scale of power system continuously extends now, so the generator number is also more and more in the system, which makes the frequency of low frequency oscillation take place closely spaced modes phenomenon easily.At this time when the system parameters take place minor changes, the system has the potential to instability.In order to restrain low-frequency oscillations and maintain the stable operation of power system, installation of power system stabilizer (PSS) is still commonly used methods.According to participation factors, PSS is installed in the generator to each of low-frequency oscillation modes.Then use of extension analytic hierarchy process determines the installation of the PSS. However, this method can not determine the priority of PSS. In this paper, the determinant method of close modes is proposed in power system.The use of matrix perturbation analysis of the closely spaced characteristics of power system found its modes instability.And the installation of PSS is studied in dense frequency system. Application of the New England 10 machine system and shanxi power grid as an example to validate the results of this paper is correct.