An adaptive bidirectional protective relay algorithm for ferroresonance in renewable energy networks

Abstract

Smart grid comprises utility system and renewable resources including wind farm and solar system. It causes bidirectional flowing of power especially in distribution level, and establishing communication facility amongst utility system, distributed generations (DG), and loads. In this study, influence of occurrence of ferroresonance in the utility system is investigated on technical quantities of DFIG and operation of directional overcurrent (DOC) relay installed in wind farm is assessed by means of PSCAD/EMTDC simulation software. Smart grid stand in need of a self-healing protection; therefore, an adaptive algorithm on the basis of neural network and signal analysis tools like, wavelet transform, moreover, analysis of ferroresonance in time domain is designated for overcurrent relay. The relay with new algorithm can conform to protection strategy of smart grid. It discriminates ferroresonance from other nonlinear and transient abnormalities, which affect deviation of electrical quantities. Protection strategy established in smart grid decides on behaviour of the relay through the algorithm. It takes an appropriate decision in ferroresonant states to modify setting quantities of the relay and changes direction of operation to enhance reliability and availability of power electricity in smart grid. The relay is capable of predicting ferroresonance in the network to fulfil smart grid requirements.