A Novel Explicit Disturbance Model-Based Robust Damping of Interarea Oscillations Through MTDC Grids Embedded in AC Systems

• Published in: IEEE transactions on power delivery 2018-08, Vol.33 (4), p.1864-1874
• Main Authors: Banerjee, Abhishek, Chaudhuri, Nilanjan Ray, Kavasseri, Rajesh G.
• Format: Article
• Language: English
• Subjects: <inline-formula xmlns:ali="http://www.niso.org/schemas/ali/1.0/" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> <tex-math notation="LaTeX"> {\mathcal H}_{\infty }</tex-math> </inline-formula>; Computer simulation; Control design; Converters; Current injection; Damping; Disturbances; Embedded systems; explicit disturbance modeling; Feedback; inter-area oscillations; Linear matrix inequality (LMI); Mathematical analysis; Mathematical model; Matrix methods; mixed-sensitivity; Moisture content; multiterminal DC (MTDC); Oscillations; Oscillators; Robust control; Robustness; Robustness (mathematics); Sensitivity; Voltage control
• ISSN: 0885-8977; 1937-4208
• DOI: 10.1109/TPWRD.2018.2799170

This paper presents a novel approach to damp interarea oscillations by designing a robust multi-input multioutput supplementary controller for multiterminal dc (MTDC) systems embedded in ac grids. The key idea to achieve robustness lies in explicitly modeling the MTDC current injection as disturbances using an {\mathcal H}_{\infty } mixed-sensitivity formulation in the linear matrix inequality framework. Control directions are established by selecting wide-area feedback signals and the relative gain array computation. Robustness is assessed through dynamic simulations for scenarios including: first, disturbances on the ac side, second, disturbances on the dc-side such as loss of a converter pole including actuator, third, partial loss of feedback signal, and fourth, communication latencies. The performance of the proposed controller is compared against the conventional {\mathcal H}_{\infty } based design, using a four-terminal dc grid embedded within the New England-New York test system. The results suggest that the proposed approach demonstrates superior performance following dc-side disturbances, actuator outages, and latency.