Robust UPFC controller design using Quantitative Feedback Theory method

An industrial plant, such a power system, always contains parametric uncertainties. In the design of a controller the uncertainties must be considered. Otherwise, if the real plant differs from the assumed plant model, a controller designed based on classical controller design approaches may not ensure the stability of the overall system. In this paper a robust controller, based on the quantitative feedback theory (QFT) approach is proposed for the design of UPFC controllers (power flow and DC-voltage regulator). As an example, we have designed a case for the system to compare the proposed method with a conventional method (classical PI controller). Validity of the proposed method has been confirmed by linear and nonlinear time domain simulation results.