PSS tuning in generators located in a manufacture plant of aluminum

The studies, simulations and tests carried out to tune power system stabilizers (PSS) are presented. These PSS are installed in gas turbine generators located in a manufacturing plant of aluminum. This plant is connected to an electric system named "Sistema Electrico Interconectado Patagonico" or SEPI, and represents the 60% of system load. The plant load particularity, strongly voltage dependent in the range of the electromechanical oscillation frequencies, and the network topology, are the major cause for different behaviors of the electrical system to the several oscillations frequencies modes. The PSS have been tuned to obtain a suitable damping of the interarea oscillations and to have a good behavior for the other electromechanical modes. The type of PSS selected and the tuning values adopted have had into account the interaction with the speed governors and the load control. The adjustments were implemented and tested in four generating units. The results of the tests are analyzed, showing a good agreement with the studies previously made.