Mode Selective Damping of Power System Electromechanical Oscillations Considering Time Delay Uncertainty in Supplementary Remote Signals

This paper presents the design of H∞-based local decentralized power system stabilizer (PSS) controllers for large-scale power systems, using selected suitable remote signals from the whole system as supplementary inputs, for a separate better damping of specific inter-area modes, considering uncertainty in time delay. System identification technique is used for deriving lower order state-space models suitable for control design. The PSS controller uses only those local and remote input signals in which the assigned single inter-area mode is most observable and is located at a generator which is most effective in controlling that mode. The PSS controller, designed for a particular single inter-area mode, also works mainly in a frequency band given by the natural frequency of the assigned mode. The effectiveness of the resulting PSS controllers is demonstrated through digital simulation studies conducted on a sixteen-machine, three-area test power system.