Damping of low-inertia machine oscillations using Takagi-Sugeno fuzzy stabiliser tuned by genetic algorithm optimisation to improve system stability

The implementation of distributed generation (DG) in a power network may introduce undesirable transients or network oscillations in power networks due to low or no inertia. These undesirable transients and oscillations may be dampened through the use of power system stabiliser (PSS), if properly designed. In this study, an intelligent PSS comprising of Takagi-Sugeno (TS) fuzzy-logic control and genetic algorithm optimisation is proposed to effectively dampen these oscillations. Eigenstudy and participation factor analysis have been carried out to determine critical issues relating to angle instability such that the intelligent PSS can be designed accordingly. The proposed fuzzy-logic stabiliser is tested on an Australian power network using network data provided by an industry participant. To demonstrate the effectiveness of the proposed fuzzy-logic PSS, a number of disturbances have been simulated and the response of the interconnected DG units of rotary type is assessed in terms of rotor angle and rotor speed. The results demonstrate that the proposed fuzzy-logic controller substantially improves the performance of the network transients with DG by effectively damping local oscillations in the machine rotor angle and machine rotor speed.