A three-stage multi-agent-based peer-to-peer method for fault isolation of high distributed generation penetrated distribution networks

As a major strategic component of smart protection schemes, quick and accurate fault isolation would significantly enhance the system performance. With the ever-increasing installation of distributed generation (DG) units in the distribution networks, however, the fault isolation has become challengeable. Using the multi-agent-based infrastructure, this paper presents a peer-to-peer decentralized protection coordination scheme having the ability to quickly isolate the fault without dependency to DGs' operating points. To do so, the distribution network is first mapped into a communication network to define the relationship tables among the protection devices as the agents. Using a three-stage algorithm, then, the faulted section is removed from the network. In this way, the agents have the ability to be informed about the operation of other agents and accordingly update their relationship tables, network configuration, short circuit level and direction of current flow. Moreover, the decentralized nature of peer-to-peer communication makes the approach capable of not relying on a central controller. The proposed method utilizes the common protection devices to be used as the agents and does not need additional measurement equipment. Numerical studies show that the proposed protection scheme can accurately and quickly isolate the faulted section of a high DG-penetrated distribution network system.