Delay-tolerant PSS with discrete-time H∞ observer-based predictor

Technological developments of GPS and PMU are enabling construction of the centralized PSS scheme which is expected to mitigate damped low frequency inter-area oscillations. Since transmission and processing delays in GPS and PMU units amount to the order of 100 ms, the centralized power systems should be endowed with robustness to those delays. This paper investigates the possibilities of designing a delay-tolerant centralized PSS as an H^∞ observer-based predictor. We accommodate uncertain delay length by employing the weighting function technique in the general H^∞ control theory. A typical multi-area multi-machine system is adopted as the benchmark target, and the proposed PSS is assessed with respect to the delay variation.