Development of the discrete-time adaptive sliding mode power system stabilizer

A newly developed discrete-time adaptive sliding mode power system stabilizer( PSS) is proposed in this paper. Because the proposed PSS is developed in the pure discrete-time domain, it is able to maintain the stability with the rather slower sampling frequency compared to discretized conventional continuous-time sliding mode PSS. The proposed PSS has the three main superiorities to the conventional PSS. First, because the proposed PSS utilizes the sliding mode control method, it has the strong robustness to the variations of the system parameters. Hence, it can overcome the minor disturbances such as identification errors, modeling errors, etc. Second, the proposed PSS needs only input/output measurements as feedback signals. Hence, it does not need the measurements of the state variables as the conventional sliding mode PSS or PSS based on the linear quadratic control method does. Finally, because the proposed PSS have the adaptivity property, it is able to overcome the various power system faults, such as line-to-line faults, line-to-ground faults, etc. To verify the performance of the developed PSS simulations with the sample power system with single-machine and infinity-bus have been performed.