Optimal Protection Scheme for Distribution Systems Integrated with Distributed Generator

Abstract

Combination between the distributed generator (DG) such as conventional distribution grid, tidal turbines, and nuclear power plant is increasing rapidly around the countries, because of its reliable and nature-friendly behaviors. Also, DGs are a major feature in a smart grid. However, this integration causes bidirectional current flows and contributes to the level of fault current especially during the power swing. Therefore, it changes the fault current pattern in the distribution network and adversely affects the coordination of the protection relays. Many papers have proposed different techniques to detect and classify the faults in distribution network and only isolate the faulty section such as (protection coordination using dual setting directional relays, Fuzzy logic based method, wavelet transform based method, Adaptive protection based techniques...etc). In the light of this situation, a comprehensive protection algorithm is proposed in this paper to detect any fault in distribution network with DGs during the power swing and guarantees a secure and reliable performance to avoid any unintentional disconnection during any fault case. The proposed protection direction scheme totally depends on the auto regression technique for the positive sequence component of currents angles difference (fault–prefault). It is better to depend on current signals only in designing smart protection systems. In this article, a proposed protection scheme depending on current signal of two terminals. The effectiveness of the proposed scheme is demonstrated compared to other methods in the literature