SIARA - System Integrity & Restorative Actions

Authors: Priyanka Mohapatra, SP Energy Networks, UK and Hao Guo, Power Networks Demonstration Center, UK

Acknowledgements: Craig McTaggart, David Adam, Graeme Duncan, and Jennifer Kincaid Mackenzie, SP Energy Networks, Prasad Balasubramani, GE Grid Solutions, Kulbhushan Kulbhushan, and Andy Wilson, commtel, and Matthias Wehinger, OMICRON Electronics

Project SIARA (System Integrity and Restorative Actions) is an innovation project led by SP Energy Networks (SPEN) that explores the feasibility of deploying wide area protection and control (WAPC) in SP Transmission (SPT) and SP Distribution (SPD) network using IEC61850-90-5 routable GOOSE (R-GOOSE).  The key objective of project SIARA is to demonstrate feasibility of use of R-GOOSE over SPEN’s wide area network (WAN) and highlight the communication, time-synchronization and other infrastructure requirements for future roll-out of R-GOOSE for WAPC applications across the SPT and SPD network.

Project SIARA proposes a new architecture based on IEC61850-90-5 R-GOOSE for the upgrade of existing and for new SIP schemes as shown on page 38. The future-roll out of this technology will include multiple substations involved in a R-GOOSE based SIP/WAPC scheme. The protection devices in non-central (remote end) substations are denoted as S/S1 to S/Sn and the controller device in the central substation is denoted as C/C1. If there is fault occurring and it is detected by S/S1, the S/S1 will initiate local protection action for example tripping the associated circuit breaker (CB) and then send R-GOOSE to the central controller C/C1. The central controller C/C1 will execute the logic in response to receiving R-GOOSE containing fault related information and subsequently send R-GOOSE command such as closing CB to all related S/Sn for example S/S2.
The offsite tests presented in this article were conducted as part of the project SIARA at Power Networks and Demonstration Centre (PNDC) and aimed to validate the use of R-GOOSE message exchange in Wide Area Network (WAN) that is setup up using packet based MPLS-TP nodes.

Performance Requirement for Communication Service
The GB Energy Network Association (ENA) Technical Specification 48-6-7 “Communication services for teleprotection system” specifies values for steady state propagation latency of 6 ms and steady state asymmetrical latency of 0.4 ms for Category 1 service.
The project SIARA also specifies the latency requirement from the perspective of application. The expected timings of the scheme are summarized in Table 1. During the tests, requirements depicted in Table 1 have been used as the reference.

Testbed Configuration
The hardware-in-the-loop testbed set-up in PNDC to carry out the offsite laboratory testing to prove the objectives of project SIARA is shown in Figure 1 and consisted of real time digital simulator, IEDs with R-GOOSE messaging, PTP time synchronization, network simulation and monitoring equipment.
A transmission line and associated electrical fault and frequency events have been simulated using the simulator as shown in Figure 1 and the response time of an IED could be measured by the simulator. In addition to the trip signal, relays also issued binary output in response to loss of R-GOOSE messages and the test system could monitor the R-GOOSE communication status.

Protecting your electrical assets? today and tomorrow