Interfacing IEC 61850 Station Bus Protection to Existing Protection in a Brown-field Substation Georgia Tech Protective Relaying Conference May 2, 2018 Donald Pratt and Mark Seiter Consolidated Edison Company of New York, Inc.

Agenda Observations and recommendations Example migration process Green-field (new) vs brown-field (existing) Understanding migration Outage sequence and configuration files Migration independent of outage sequence Example migration process Project description Cataloging existing system Recognizing functional elements and fitting them to the data model Data acquisition and devices with common configurations Conclusions

Green-field vs brown-field new new new old old old old new old old new new B1 B2 B3 31 12 23 Brown-field (complicated by interface between “new” and “old”) Outage sequence B1 then B2 then B3 Outage 1: new, old, old Outage 2: new, new, old Outage 3: new, new, new

Understanding migration System Operations SCADA migration Points are tied to the primary equipment outage RTU I/O RTU I/O Commissioned Outage 1 Commissioned Outage 2 Retired Outage 1 Retired Outage 2

Understanding migration System Operations Protection migration Points are tied to what is adjacent to the primary outage RTU I/O Data Concentrator IED Interface Interface Retired Outage 1 Retired Outage 3 Retired Outage 2

Outage sequence and configuration files Example of “new-new” with a bus fault Representation of GOOSE communication Publisher TRIP X Message Subscriber BF INIT Circuit Breaker Interface BF TRIP

Outage sequence and configuration files Example of “new-old” with a bus fault TRIP Configuration change required Line Diff. Relay & CBI Must now subscribe to Interface X LOCKOUT OPERATION BF INIT TRIP BF TRIP

Migration independent of outage sequence Outage sequence may change 29 major outages over 5 year project installation schedule Create flexibility by over-designing the publisher-subscriber relationships Consider each section to be the first commissioned Identify all publisher-subscriber relationships to interface “new-old” Consider each section in the final configuration Identify all publisher-subscriber relationships for “new-new” This covers all possible combinations All sequence possibilities may be verified during acceptance testing

Migration independent of outage sequence Buying greater flexibility Field engineers may adjust to outage sequence changes without modifying configurations Reduced engineering during time-constrained outage windows Not without cost Paying for it with added complexity Not all publisher-subscriber relationships will be used Only one of any two busses can be commissioned first Communication alarms will need to be suppressed When publishers stop publishing, subscribers alarm

Project description 345 kV 8 feeders. 8 autotransformers, 4 GIS breaker assemblies 138 kV 7 feeders, 12 bus sections, 33 breakers 21 pressurization and cooling plants

Project description Typical arrangement “old-new” interface New GIS breaker Typical arrangement Outage Sequence One pair of feeders at a time A full outage season 29 outages 5 year schedule “old-new” interface On the 138kV bus sections Interface not obvious B (Bus) F (Feeder) T (Transformer)

Cataloging existing system Capture each point in a spreadsheet Data is used to inform interface device decisions Identify outage when points are commissioned and retired B Bus data T T Breaker Data

Recognizing functional elements and fitting them to the data model The migration plan is an effort to surrogate the devices that the new data model is expecting, but are not currently installed

Data acquisition and devices with common configurations Bus1 Data Bus2 Data Parsimonious vs lavish design Bus section “data” is similar bus to bus Bus, Feeder, and Transformer data Lockout count Parsimonious Design only for the bus its on Lavish (one size fits all) Design for “max case” of each data type Only wire what is needed Configuration is common GOOSE data set is uniform B F T B T F Bus3 Data B T Interface Device Requirement T F B

Conclusion Observations and recommendations IEC 61850 and migration Protection migration should be included in the project specification Bid evaluations should heavily weight the migration plan Migration plan should be designed to require no configuration modifications for changes in outage sequence IEC 61850 and migration The project specification should include a catalog of the existing system The migration process should use the existing system to fill in the missing portions of the new systems data model Common configurations should be developed to support a uniform data model