Design of a wide area damping controller based on partial right eigenstructure assignment

•Designed a WAC using partial right eigenstructure assignment.•A quadratic programming formulation has been presented.•Closed-loop eigenvectors have been assigned using projection techniques.•Multi-model optimization has been used to address the time delay of feedback signals.

The paper demonstrates the application of partial right eigenstructure assignment for designing an output-feedback based wide area damping controller in a power system. The unique feature of the controller is that it utilizes the additional design freedom provided by right eigenvectors along with eigenvalue placement to improve the dynamic behaviour of the system. The fact that multi-input–multi-output (MIMO) systems provide more design freedom than just manipulating the eigenvalues of the system has been exploited for controller design. Supplementary loops on two static VAR compensators (SVC) have been used utilized to achieve the damping of oscillations. The first part of the paper uses a quadratic optimization based formulation to design a controller for a nominal operating point of the system. The second part demonstrates the incorporation of time delay of feedback signals in controller design. This methodology makes the designed controller robust to uncertainty in communication latency of feedback signals. The feedback signal selection for the controller is based on an input/output controllability metric specific to output feedback. An algorithm explaining the framework and the results of its implementation on the IEEE 68 bus test system has been provided. The results show the effectiveness of the controller to damp oscillations and robustification of the damping of these oscillations to time delay uncertainties.