1. International Scientific & Technical Conference
Digital Energy Multilin
Reducing Conventional Copper Signaling in High Voltage Substations with IEC Process Bus System
David McGinn, GE Digital Energy Maciej Goraj, GE Digital Energy Jorge Cardenas, GE Digital Energy
International Scientific & Technical Conference
“Actual Trends in Developments of Power System Protection and Automation”, 7-10 September 2009, Moscow

2. Business Drivers for Process Bus
Robust and practical process bus architecture is a missing element on the road to implementing the next generation of Protection and Control (P&C) systems
Successful technical solutions are those that are simple and that address well-defined real problems
Achieving cost savings
Reducing project duration

3. P&C System Cost Breakdown
“The next generation P&C system should replace copper wiring by placing electronic modules throughout the switchyard and using fiber communications for bi-directional exchange of data”

4. Design Principles

5. Process Bus System Principles
Copper connections - the largest source of variability and cost:
Replace custom copper connections with standard, pre-terminated fiber optic connections
Migrate physical variability of connections into software and fiber connectivity
Before …
… After

6. Design Principles
Standard magnetic ITs will be in service for a long time:
Not dependant on installation of non-conventional ITs, but
Support non-conventional ITs as market acceptance grows

7. Design Principles Maintain traditional P&C concepts:
Overlapping and independent zones of protection
One independent device protecting one zone
Minimum inter-dependencies
Not all the process data is needed by all IEDs. The limited data requirements of each IED are clearly and unambiguously dictated by the virtually fixed power primary equipment arrangement.

8. System Architecture

9. System Architecture
Process bus Merging Units installed in the switchyard at direct proximity to HV primary equipment
Provide complete I/O capability for the system
Interface all types of switchgear (CBs+CTs, PTs, free-standing CTs, disconnect and ground switches, sensors)
Data acquisition and outputs only, no processing (future-proof)
Redundant MUs for critical signals
No conventional I/Os in IEDs in relay cabinets
No extra devices in the system (LAN switches, master clocks)

10. System Architecture
Merging Units connected via multi-fiber cables (star topology)
Fiber cables in trenches, directly buried when required
Merging Units powered via copper wires integrated in the fiber cable
Prefabricated high-density cable connectors
Outdoor
fiber
cables
Switchyard
Control house

11. System Architecture

12. System Components

13. System Components

14. Outdoor Mounting Scenarios
External, on a Circuit Breaker
External, on a structure
External on VT, CT marshalling box
Internal, old oil-type Circuit Breaker
Etc.,

15. Advanced Issues
Data sharing
Synchronization
Independence of devices

16. Multiple MUs in One Physical Device
Four independent “digital cores”
Direct point-to-point fiber link to relay
Digital communication with data integrity
Analog Core
Common I/O
hardware

17. The only tools you will ever need
Making the Connection

18. Synchronization IED 3 Merging Unit IED 4
Four independent “digital cores”
IED 3
Merging Unit
Up to 4 independent relays can connect to a MU. Each relay can send an independent “Convert” pulse to the virtual A/D converter in each Digital Core. This eliminates the need for a global substation clock.
IED 4
Devices stay independent – - no need for a master clock

19. Synchronization

20. Summary Architecture Rugged units to interface all switchyard I/O
Point to point communication to relays
Relays as synch masters
Multiple MUs inside a physical device
Comprehensive all-fiber P&C system
Reduces installation & maintenance cost
Intuitive & practical IEC process bus
Modular & scalable
Improves quality, reliability