A new local backup scheme considering simultaneous faults of protection IEDs in an IEC 61850-based substation

• A new local backup scheme to consider simultaneous fault of IEDs.
• An improved local backup IED in IEC 61850-based substation.
• New monitoring concept by self-supervision in IEC 61850-based substation.
• Optimal number of the proposed local backup IED for IEC 61850-based substation.
• Implementation of the proposed local backup scheme.

Importance of protection IEDs in IEC 61850-based substations has increased by enhancing performance of IEDs but local backup scheme in the substation is not considered important. In the existing local backup method, two protection IEDs are installed for one protection target. This method is useful for local backup of the IEDs. However, local backup at simultaneous fault of the protection IEDs is not performed in conventional substation because it has limitations on operational environment. However, IEC 61850-based substation improves operational environment with high speed communication network and high performance IEDs; and the simultaneous fault problem can be resolved by developing new devices and schemes. Therefore, this paper proposes a new local backup scheme for simultaneous faults of protection IEDs in an IEC 61850-based substation. The proposed backup scheme is configured as self-supervision-based monitoring, new improved local backup IED, and local backup scheme; and the proposed scheme is implemented and tested using IEC 61850 SISCO library on a laboratory test bed.