Digital Twin Application for the Evaluation of Protection Performance in IEC-61850-Based Digital Substations

A digital substation represents a significant advancement in the field of electrical infrastructure. Unlike conventional substations that rely heavily on analog equipment and manual operations, digital substations embrace automation, data exchange, and real-time monitoring. To secure the interoperability of the communication equipment in the digital substation, IEC 61850 standard is employed for information transformation between devices in the substation. Meanwhile, the data sharing availability in digital substations enhances the protection system to reflect the state of change of the power system, huge amount of data on the local area network (LAN) may cause some problems to the protective intelligent electronic devices (IEDs). The objective of this paper is to develop a digital twin application for evaluating the performance of protection IEDs in IEC 61850 based digital substation. Instead of requiring an expensive real-time digital simulator and actual merging units (MUs), Power System Computer-Aided Design (PSCAD) with digital twin MUs are employed. To evaluate the performance of the digital twin application, a substation simulation model is built on PSCAD/EMTDC simulator, and a single to ground fault detection algorithm for unground distribution is performed on the protection IEDs. Testing results show that the twin application operates properly to generate electrical current and signal and publish sample values (SVs) to the network. Moreover, generic object-oriented substation events (GOOSE) message which is published by protection IEDs is subscribed by circuit breaker management (CBM) and used for controlling circuit breaker model on PSCAD.