Power Oscillations Damping Controller for HVDC Inserted in Meshed AC Grids

Abstract

This paper addresses the problem of damping interarea oscillations via power modulation of a VSC-HVDC link integrated in a power AC grid. Motivated by the fact that interarea modes may be at higher frequencies, close to other modes of the system, and classic tuning methods of standard (IEEE) power oscillations damping controller structures may not give satisfactory results. A reduced order model of a meshed AC grid with a HVDC link is proposed for control design. Based on this model which carefully integrates the dynamics of interest, a robust controller for the HVDC link is designed to damp interarea oscillations and enhance the damping of the other modes. Investigations with both linearized and nonlinear model of the system are carried out to settle and validate the approach. The efficiency and robustness of the proposed controller are tested and compared with standard controller structures.