Global tuning of power-system stabilizers in multi-machine systems

This paper presents a global tuning procedure for conventional PSSs in a mu lti-machine power system using a non-linear optimization algorithm implemen ted in a simulation program. The main objective of this procedure is to sim ultaneously optimize pre-selected parameters of those PSSs having fixed par ameters in coping with the complex non-linear natures of the power system. By minimizing a non-explicit target function in which the oscillatory rotor modes of the generators involved and swing characteristics between areas a re included, overall power oscillations at transient conditions in the mult i-machine system are improved. A four-machine power system is applied to de monstrate the efficiency and robustness of the presented tuning procedure. The results obtained from simulations validate the improvement in damping o f overall power oscillations in the system. The simulation also shows that the optimized PSSs are robust in providing adequate damping for a range of conditions on the system. (C) 2001 Elsevier Science B.V. All rights reserve d.