| Publisher | IEC |
|---|---|
| Type | Standard (multi-part international series) |
| Scope | Communication networks, data models, configuration language and conformance testing for automation and protection systems in power utilities, originally substations. |
| Who uses it | Protection and control engineers, substation automation integrators, utility engineers, relay manufacturers, network engineers and commissioning teams. |
| Edition note | Each part of the series has its own edition. Refer to the publisher for the current edition of each part. |
What It Is
IEC 61850 is a series of international standards that defines how intelligent electronic devices (IEDs) in a power system describe, exchange and act on information. Its central idea is to separate the data model from the communication technology. Functions such as overcurrent protection, circuit breaker control or measurement are represented as standardized logical nodes with defined data objects, and those models are then mapped onto specific communication services.
The series includes a system configuration language (SCL, defined in part 6) that describes devices, communication networks and the substation itself in standard XML files. It defines mappings to MMS for client-server communication and to GOOSE for fast peer-to-peer event messages (part 8-1), and sampled values for streaming digitized current and voltage measurements over a process bus (part 9-2). Part 10 addresses conformance testing. Over time, the scope has expanded beyond substations to areas such as distributed energy resources, hydro plants and wind power.
Why It Matters
Before IEC 61850, substations relied heavily on proprietary protocols and extensive copper wiring between devices. The standard enables multi-vendor interoperability, reduces wiring, supports engineering tools that work from a single system description and allows advanced schemes such as interlocking and breaker failure protection to be implemented over Ethernet.
The shift also changes the skill set required. Protection engineers now need to understand networks, time synchronization, cybersecurity and configuration file management, and commissioning increasingly involves testing virtual signals rather than physical wires. Adoption is rarely all-or-nothing. Many utilities begin with station bus communication and GOOSE messaging, then move toward process bus and sampled values as experience grows. Each step requires disciplined configuration management, because the SCL files that describe the system become as important as the drawings that once documented hard-wired schemes.
Key Concepts
- Logical nodes — standardized function models with defined names, such as XCBR for a circuit breaker and PTOC for time overcurrent protection.
- Substation Configuration Language (SCL) — XML-based files, such as ICD, CID, SSD and SCD, that describe devices, communication and the substation for engineering tools.
- GOOSE — fast multicast messages used for trip signals, interlocking and status exchange between IEDs.
- Sampled values — streams of digitized analog measurements sent from merging units over a process bus.
- Station bus and process bus — network layers connecting IEDs to station systems and to primary equipment interfaces respectively.
- Time synchronization — accurate time distribution, often using precision time protocol, required for sampled values and event recording.
- Redundancy protocols — PRP and HSR, defined in IEC 62439-3, provide seamless network redundancy for critical traffic.
- Conformance testing — procedures in part 10 for verifying that devices implement the standard correctly, supporting multi-vendor interoperability.
Who Should Know It
- Protection and control engineers
- Substation automation and SCADA integrators
- Commissioning and testing engineers
- Utility network and cybersecurity engineers
- Relay and IED product specialists
Related Standards
- IEC 60255 — defines requirements for the protection relays that implement IEC 61850 functions.
- IEEE C37 Series — includes protection guides and standards such as COMTRADE and synchrophasor standards used alongside IEC 61850.
- IEC 62271 — covers the switchgear that IEC 61850 systems monitor and control.
- IEC 62351 — the IEC series addressing cybersecurity for power system communication, including IEC 61850.
How ASEEE Uses It
ASEEE protection and substation programs map learning outcomes and assessments to IEC 61850 concepts, including data modeling, configuration files, GOOSE and sampled values, and testing practice. See related ASEEE programs.
ASEEE Programs Referencing This Standard
Educational summary only. ASEEE is not the publisher of this document and this page does not reproduce or replace it. Always consult the current official edition from IEC for requirements.