Abstract:

In order to design a decentralized H∞ controller with robustness and low dimension, the polytopic model is employed to describe the operation states of uncertain power systems as a convex set, in which the vertices are some typical operation parameters, and the homotopy parameter method is adopted to interactively solve two linear matrix inequalities for the purpose of obtaining the solutions to the controller. The proposed approach is then used to design a decentralized additive damping controller in the static var compensator （SVC） and a power system stabilizer （PSS） in an IEEE benchmark system with 19 generators. The test results show that, due to their mutual coordina- tion, the decentralized controller not only greatly improves the damping ratio and anti-interference capability of pow- er systems, but also effectively restrains the continuous oscillations resulting from serious faults. It is also demon- strated that the proposed approach in combination with the model reduction method can further reduce computational burden and is thus suitable for practical power systems.

Key words: power system, uncertainty, damping control, polytope, low-dimension controller, decentralized H&infin, controller