IEC 61850 is an international standard for communication between intelligent electronic devices (IEDs) in electrical substation automation systems. It sets out how those devices describe themselves and exchange data, so a substation can be built from equipment made by more than one manufacturer without a separate integration for each pair.
The International Electrotechnical Commission developed it to deal with the growing complexity of power systems and the need for a standardised way to communicate in smart grid applications. It covers four things:
- Data modelling
- Communication protocols
- Engineering processes
- Compliance testing
Key features
Object-oriented data model
The standard represents power system devices and functions as objects. This model, the Abstract Communication Service Interface (ACSI), defines logical nodes and data objects that correspond to real-world power system components.
Standardised communication services
Three protocols do most of the work:
- Generic Object-Oriented Substation Event (GOOSE) for fast, real-time communication
- Sampled Values (SV) for transmitting analogue data
- Manufacturing Message Specification (MMS) for client-server communication
Substation Configuration Language
SCL is an XML-based language for describing substation configurations. It carries configuration data between engineering tools and IEDs, which is what makes system design and maintenance portable between vendors.
Time synchronisation
The standard specifies time synchronisation, so events and measurements across the network carry timestamps that can be compared.
What adoption gives a substation
- Interoperability: devices from different manufacturers can exchange data without per-vendor integration work.
- Flexibility: the object model allows substation systems to be extended or changed without extensive reconfiguration.
- Less wiring: Ethernet-based communication reduces the amount of copper wiring a substation needs.
- Diagnostics: the standard includes diagnostic features that shorten fault finding and maintenance.
- Longevity: the standard continues to be revised, so an implementation is not tied to one generation of equipment.
Where EpiSensor fits
EpiSensor hardware and software can be used alongside compliant systems to:
- Collect real-time energy data from substation equipment
- Monitor power quality and performance metrics
- Implement demand response
- Contribute to grid stability and reliability
EpiSensor’s Zigbee wireless sensors and gateways can be configured to communicate with compliant devices, so they can be added to an existing substation automation system. EpiSensor Edge processes and visualises the data those networks produce.
Where it is difficult to adopt
- Complexity: the standard is comprehensive, which makes a first implementation long and detailed work.
- Cybersecurity: as with any networked system, the security measures have to be designed in rather than added afterwards.
- Training: personnel need time to learn the model before they can work with it effectively.
- Migration: moving from legacy systems to compliant infrastructure is a substantial undertaking.
What it means for the grid
A common framework for communication and data modelling is what makes a substation extensible. As more distributed generation and more flexible demand connect at that level, the standard matters more, because the alternative is a bespoke integration for every device.
EpiSensor’s systems add data collection, analysis and visualisation alongside a compliant substation, which is where energy monitoring, demand response and energy management programmes are built.
