Reliability Analysis of Cyber-Physical Systems: Case of the Substation Based on the IEC 61850 Standard in China

With the increasing interaction between physical devices and communication components, the substation based on the IEC 61850 standard is a type of cyber-physical system. This paper proposes a reliability analysis method for substations with a cyber-physical interface matrix (CPIM). This method calculates the influences from both the physical device failures and the communication devices failures. Two indices, Probability of Load Curtailments and Expected Demand Not Supplied, are used in the reliability analysis. Given the simplified model of the practical substation based on the Chinese IEC 61850 standard, the results show that the substation system had a potential risk of cascading failure under the cyber-physical fusion trend, as the failure in cyber layer would increase the power loss of the whole system. The changing magnitude of Expected Demand Not Supplied increased significantly with increasing transmission delay rate of the process bus.