Contribution of high voltage direct current transmission systems to inter-area oscillation damping: A review

The cumulative advancements on high voltage high current fully controlled semiconductor switching technology have led to positive progress for high voltage direct current (HVDC) systems for management and optimization of future power systems with large penetration of renewables in the form of distributed generation (DG). Inter-area oscillation is a natural power system phenomena that can be resulted from the oscillation of two distant groups of generators against each other with low or negative damping, causing to avoid maximum power transfer and system blackout at the worst case. Moreover, high penetration of DG can positively or negatively change the dynamic characteristics of power systems and affects system stability in terms of low frequency inter-area oscillations. Due to its flexibility and almost instant response, HVDC applications with a modified control scheme can offer a great advantage to transmission system control such as damping inter-area oscillations. This paper focuses on supplementary control strategies for damping inter-area oscillations with HVDC systems in the context of renewable DG penetration. First, detection methods for inter-area oscillations are summarized with a brief mathematical framework for each. Later on up-to-date HVDC transmission technology, including its development, converter topologies, operating configurations, and some recent HVDC projects are discussed from its preliminary historical development. HVDC converter modelling approaches and converter control techniques available in recent stability studies are also addressed. Finally, state of the art HVDC damping strategies are classified according to the way of generating damping signals with an emphasis on input signal selection, study system, and simulation tool. It is found that besides many simulation based validations for inter-area oscillation damping of HVDC systems, few practical application examples also exist, which are detailed to some extend paper by paper. Suggestions for future research directions are also incorporated.