Adaptive Overcurrent Protection Scheme for Distribution Network Integrated With Distributed Energy Resources

Abstract

With the Advent of Distributed Energy Resources (DERs) technologies its integration into Distribution networks (DN) has been growing exponentially. Integration of DERs into the existing network affects the protection coordination - mainly over current protection which gives rise to problems such as false tripping and blinding of overcurrent relays. DERs introduce an additional source of fault current and cause bidirectional power flow. Amongst protective relaying challenges, the major issue is the dynamically changing network topology of the distribution system. To address cited issues, a communication-assisted overcurrent protection scheme is discussed in this paper. In addition, a local adaptive protection scheme based on local measurements is also proposed for relatively small systems where communication architecture is not possible. The proposed local adaptive protection scheme can be used in the case of communication failure also. The effectiveness of the proposed scheme(s) is tested on the 5-bus distribution network to validate the efficacy.