A robust H/sup ∞/ power system stabilizer with no adverse effect on shaft torsional modes

AN IMPROVED H∞ POWER SYSTEM STABILIZER

“…To obtain the best possible controller satisfying the performance and robustness coordination (4), the weights W1(s) and W3(s) are iteratively adjusted as it was reported in [9][10][11]. Note that tip(s), tio(s),Wj(s) and W2(s) are stable functions.…”

“…In this system, the use of high gain, fast speed exciter can cause the dominant plant poles to move from a stable region to an unstable region depending on operating conditions. As mentioned before the standard approaches [9][10][11] are not suitable for such situations. However, the proposed approach does.…”

“…Besides the fact that many classical design objectives are included in H design, it also presents a natural tool for successfully modeling plant uncertainties. Recently, H" algorithm has been proposed to design PSSs that can maintain the system robustness [8][9][10][11]. In these standard H approaches, the following issues have been addressed: (i) Robust stabilization of the closed-loop system for all possible pre-specified uncertainties.…”

“…These limitations come from the fact that for the sake of simplicity, all the standard approaches adopt the multiplicative and/or additive forms of uncertainty representation [9][10][11]. Major limitations of the standard H" approach are:…”

A design for robust power system stabilizer by means of H∞ control and particle swarm optimization method

“…H ∞ control theory is a representative form of robust control theory, and has been used in the design of PSS [6][7][8]. Moreover, several methods, including a method that takes into consideration the problem of pole zero cancellation and a method to select an appropriate weighting function, have been proposed [9,10] in order to improve the robustness and control performance of standard H ∞ control.…”