Tuning of power system controllers using symbolic eigensensitivity analysis and linear programming

In this paper, a systematic method for the tuning of multiple power system controllers using symbolic eigensensitivity analysis and linear programming is presented. The concept of eigenvalue sensitivity is used here to formulate the linear first-order variation of the real part of the dominant system eigenvalue as a symbolic function of controller parameters. This eigenvalue variation is minimized iteratively subject to linear equality and inequality constraints. All controller parameters are tuned correctly when the objective function meets the desired performance criteria. In this method, no special assumptions are made on the type of power devices and linear feedback controllers present in the system. The proposed method is illustrated with three examples of a single-machine system with a power system stabilizer and a controller for a thyristor-controlled series capacitor. The tested configurations are supplemented with nonlinear time-domain simulations validating the small-signal stability results