International Scientific & Technical Conference Digital Energy Multilin Reducing Conventional Copper Signaling in High Voltage Substations with IEC 61850 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

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

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”

Design Principles

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

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

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.

System Architecture

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)

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

System Architecture

System Components

System Components

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.,

Advanced Issues Data sharing Synchronization Independence of devices

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

The only tools you will ever need Making the Connection

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

Synchronization

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 61850 process bus Modular & scalable Improves quality, reliability