Digital design of a power system stabilizer for a power system based on plant input mapping

This paper is concerned with the plant modeling for the digital redesign of a continuous-time power system stabilizer PSS for a single machine power system using Plant-Input-Mapping PIM method. The traditional approach has been to use the bilinear transform (Tustin’s method), but this needs small sampling intervals which gives some difficulties with modern control. The presented technique guarantees the stability for any sampling rate as well as it takes closed-loop characteristics into consideration. The proposed technique is successfully applied to the discretization of the conventional continuous time PSS for single-machine power system. For comparison studies the proposed technique is compared with conventional continuous-time PSS and Tustin’s PSS. The simulation results show that the states of the proposed digital redesign technique closely match those of the conventional continuous-time PSS. The proposed digital redesign technique guarantees stability even with relatively slow sampling rates while Tustin’s method falls when sampling interval becomes larger.

► Conventional PSS is used in power system to damp the low frequency oscillations.
► The study system is fourth order linearized model of one machine power system.
► The paper is concerned with the discretization of a conventional PSS.
► The PIM digital design method is used to discretize the conventional PSS.
► For comparison, discrete PSS is compared with conventional PSS and Tustin’s PSS.