Coordinated Control of Multiterminal DC Grid Power Injections for Improved Rotor-Angle Stability Based on Lyapunov Theory

• Published in: IEEE transactions on power delivery Vol. 29; no. 4; pp. 1789 - 1797
• Main Author: Eriksson, Robert
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.08.2014; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Control Lyapunov function; Control systems; coordinated control; Direct current; Direct current networks; Disturbances; Electrical engineering. Electrical power engineering; Electrical machines; Electrical power engineering; energy function; Exact sciences and technology; high-voltage direct current (HVDC); HVDC transmission; Lyapunov methods; Matlab; multiterminal dc (MTDC); Nonlinearity; Power networks and lines; Power system stability; Regulation and control; small-signal stability; Stability; Stability criteria; Strategy; Time optimal; Trajectory; Transient analysis; transient stability; Energy function; Small signal behavior; MATLAB software; high-voltage direct current (HVDC); Feedback regulation; Three phase fault; Transient stability; Implementation; coordinated control; Direct current; multiterminal de (MTDC); Multiterminal networks; HVDC systems; Small signal; Control system; Synchronism; Rotor; Bang bang control; High voltage; High current; Optimal control; System simulation; Control Lyapunov function; small-signal stability; Interconnected system; Lyapunov function
• ISSN: 0885-8977; 1937-4208; 1937-4208
• DOI: 10.1109/TPWRD.2013.2293198

The stability of an interconnected ac/dc system is affected by disturbances occurring in the system. Disturbances, such as three-phase faults, may jeopardize the rotor-angle stability and, thus, the generators fall out of synchronism. The possibility of fast change of the injected powers by the multiterminal dc grid can, by proper control action, enhance this stability. This paper proposes a new time optimal control strategy for the injected power of multiterminal dc grids to enhance the rotor-angle stability. The controller is time optimal, since it reduces the impact of a disturbance as fast as possible, and is based on Lyapunov theory considering the nonlinear behavior. The time optimal controller is of a bang-bang type and uses wide-area measurements as feedback signals. Nonlinear simulations are run in the Nordic32 test system implemented in PowerFactory/DIgSILENT with an interface to Matlab where the controller is implemented.