Biblio

Modern power systems today are protected and controlled increasingly by embedded systems of computing technologies with a great degree of collaboration enabled by communication. Energy cyber-physical systems such as power systems infrastructures are increasingly vulnerable to cyber-attacks on the protection and control layer. We present a method of securing protective relays from malicious change in protective relay settings via collaboration of devices. Each device checks the proposed setting changes of its neighboring devices for consistency and coordination with its own settings using setting rules based on relay coordination principles. The method is enabled via peer-to-peer communication between IEDs. It is validated in a cyber-physical test bed containing a real time digital simulator and actual relays that communicate via IEC 61850 GOOSE messages. Test results showed improvement in cyber physical security by using domain based rules to block malicious changes in protection settings caused by simulated cyber-attacks. The method promotes the use of defense systems that are aware of the physical systems which they are designed to secure.

With the development of the interconnection of all things(IoT), a large number of mobile terminal devices with multiple users access the distribution network, and gradually form an open and interconnected network environment, which brings new challenges to the security and protection of the distribution network. In this paper, a method of analyzing the sensing data of the digital substation is proposed, which can prevent the abnormal data from causing the malfunction of the protective relays by calculating the creditability of the sensing data. Creditability calculation algorithm as well as the implementation of the intrusion tolerance strategy are studied throughout the paper. The simulation results show that the proposed creditability-based intrusion-tolerant(CIT) algorithm can ensure that the protective equipment have no protective malfunction from the false instructions or false data attacks, and the proposed intrusion tolerant algorithm has little affect on the real-time performance of the original protection algorithm, hence it has some practical value.