Frequency domain methods for stability assessment of grid-connected converters - An overview

Paper in proceeding, 2017

Being an essential part of modern electrical systems, power electronic converters provide flexibility and advanced controllability in the applications that utilise them. At the same time, the introductions of such converters in systems affects the overall dynamic behaviour of the latter. The stability of such systems can be investigated from different perspectives, e.g. time-domain observation, eigenvalue analysis, or frequency-domain analysis. The aim of this paper is to provide an in-depth overview on two of the most popular frequency-domain methods for stability assessment of systems utilising grid-connected converters: the passivity approach and the net-damping criterion. The importance of proper system modelling is highlighted while advantages and pitfalls of the two methods are investigated. The considered frequency-domain methods are applied on a variety of systems, whose dynamic behaviour is regarded both from the ac and dc side of the converters.