Use of fractional-order power system stabilizers to damp electromechanical swings in the power system

The article defines the structure of a new fractional-order power system stabilizer PSS3B_FRAC based on a modification of the structure of the typical PSS3B stabilizer. Examples of the use of this type of stabilizers to damp electromechanical swings in single-machine and multi-machine power systems are presented. It was proposed to determine the parameters of such stabilizers using optimization methods by minimizing appropriately defined objective functions. The benefits resulting from the introduction of additional parameters in the PSS3B_FRAC stabilizer model, related to fractional-order differentiation of signals in the input paths of the system, are presented. It has been shown that the PSS3B_FRAC stabilizers damp electromechanical swings better than the PSS3B stabilizers, without significant deterioration of the node voltage waveforms. Sample calculations were performed for the following models: a single-machine system and a seven-machine CIGRE system.