Robust Design of a TCSC Oscillation Damping Controller in a Weak 500-kV Interconnection Considering Multiple Power Flow Scenarios and External Disturbances

• Published in: IEEE transactions on power systems Vol. 24; no. 1; pp. 226 - 236
• Main Authors: Simoes, A.M., Savelli, D.C., Pellanda, P.C., Martins, N., Apkarian, P.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.02.2009; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Constraint optimization; Control design; Controllers; Damping; Design engineering; disturbance rejection; Disturbances; electromechanical oscillations; FACTS; Frequency; frequency response; Interconnection; large scale systems; Load flow; Mathematical models; modal analysis; nonsmooth optimization; Optimization techniques; Oscillation modes; Oscillations; Power capacitors; Power flow; Power generation; Robust control; Signal synthesis; small-signal stability; Thyristors; Time domain analysis; time-domain constraints
• ISSN: 0885-8950; 1558-0679
• DOI: 10.1109/TPWRS.2008.2006999

The power oscillation damping (POD) controllers implemented in the two thyristor controlled series compensators of the Brazilian North-South (NS) interconnection, in the year 1999, were solely intended to damp the low-frequency NS oscillation mode. These controllers are still under operation and are derived from the modulus of the active power flow in the NS line that is phase-lagged at the frequency of the NS mode and may experience relatively large excursions generated by exogenous disturbances. This paper utilizes the same 1999 data to compare the performance of a proposed robust POD controller design with those of two conventional designs. A recent robust control synthesis algorithm used in this work is based on a nonsmooth optimization technique and has the capability to handle various controller structures, including reduced-order, and to deal with time-domain constraints on both controlled and measured outputs. Moreover, the nonsmooth design technique encompasses multiple operating conditions subject to various test signals, hence building a truly time-domain multi-scenarios approach. According to the results discussed hereafter, this is a key advantage in the industrial context of increasing demand for performance and robustness. The described results relate to a large-scale system model used in the feasibility studies for that interconnection.