Applying a robust control technique to damp low frequency oscillations in the WECC

This paper demonstrates the application of a robust technique for damping low frequency oscillations in the WECC. The control is designed by extending the logic of SMA and integrating it with the LMI technique to develop a single-gain feedback controller that is capable of damping oscillations in large systems. It is an integrated form of control because it combines different controllers together so as to prevent any negative interaction between the individual controls. The proposed technique is initially applied to an equivalent model of the WECC system developed in MATLAB and then transferred to a larger and more detailed version created in PSLF. The controllers initially used for the design are the two HVDC lines and an SVC. Three ESDs are added to the model for the improvement of the control. The results indicate that the technique proposed in this paper provides adequate damping to the relevant modes of oscillations and that it can be easily applied to large and complex power system networks.

► Developed a robust control technique for damping low frequency oscillations.
► Made the control work on a 4000+ bus model of the WECC system.
► Extended logic of SMA and integrated it with the LMI-polytopic approach.
► Proposed controller prevented any negative interaction between individual controls.
► Single-gain controller damped oscillations for variety of operating conditions.