Say goodbye to power outages by taking IEC 61850 wireless

In March 2023, multiple storm systems hit California, leaving more than 100,000 customers without power. With disruptive weather events like these becoming more commonplace, power utilities are embracing distribution automation (DA) as they look for new ways to minimise outage areas and make their electricity services more reliable.

The IEC 61850 standard suite provides the digital communications foundation that utilities need for DA applications such as fault location, isolation and service restoration (FLISR), which can play a pivotal role in improving standard reliability metrics.

To deploy FLISR and other IEC 61850 applications, utilities need a field area network (FAN) with extensive cellular wireless coverage across the feeder domain in the distribution grid. The FAN must also be resilient and highly reliable so that it can support uninterrupted FLISR in the midst of a storm.

IEC 61850: Standards-based communication for grid automation

The trajectory of IEC 61850 can be traced back 20 years. In 2003, IEC Technical Committee 57 published the first edition of the IEC 61850 standard, which aimed to enable the open and interoperable digital information exchanges required for substation automation applications.

As the needs of power utilities evolved and demand for automation grew, IEC TC 57 expanded its scope beyond substations to enable automation across the grid. Today, utilities can use IEC 61850 for automation between substations, for automation between substations, control centres and data centres, and for DA in the feeder domain. 

This is a significant development for utilities. For example, having the ability to automate protection, monitoring and operations in the feeder domain of distribution grids allows utilities to improve service reliability, operational efficiency and sustainability. 

IEC TR 61850-90-6:2018 defines use cases for typical DA applications in the feeder domain that require information exchanges between two or more systems, including FLISR, fault indication and reporting, centralised voltage and var control, anti-islanding protection, automatic transfer switch, energy flow monitoring and intelligent electronic device (IED) configuration. It also provides guidelines for the communication architecture and services required to support these use cases.

Using FLISR to improve distribution grid reliability

FLISR is one of the more interesting DA applications. When a fault occurs in the feeder domain, FLISR aims to quickly locate and isolate it in the feeder domain to maintain safety, minimise the duration and impact of power interruptions, and improve the reliability of the grid.

The benefits of FLISR have been well recognised. Back in 2016, a US Department of Energy study on DA revealed that FLISR can reduce the number of customers interrupted (CI) by up to 55% and the number of customer minutes of interruption (CMI) by up to 53%. However, with severe weather events causing widespread disruption on an increasingly frequent basis, FLISR has quickly attracted more attention from utilities and government regulators seeking to keep the lights on.

The beauty of FLISR is that it is a smart, self-healing application that restores power without human intervention.

For example, when a tree branch falls on a feeder circuit and causes a fault, the FLISR application detects it and identifies its location, then uses smart self-healing logic in the FLISR controller to safely bring power back to customers. The FLISR controller, which is typically integrated with the advanced distribution management system (ADMS), geographic information system (GIS) and outage management system (OMS), restores power by reconfiguring the line switches to connect homes outside the affected circuit section to another substation.

FLISR deployment comes in different flavours, as explained in IEC TR 61850-90-6:

• Based on centralised control: When a fault occurs, the main breaker trips, recloses one or more times, and then remains open. Information transmitted to the control centre helps the system or operator locate the fault and then send commands to isolate it, reclose the feeder breaker and restore power to the healthy upstream feeder section.

• Based on distributed control: The feeder equipment controller locates and isolates faults and restores service to healthy sections based on information exchanges among the IEDs that control the main breaker in the substation and the sectionaliser switches in the feeders.

• Based on local control: When a fault occurs on a feeder, the sectionalisers react to it by autonomously opening or closing according to local overcurrent or voltage measurements. The decisions are made locally, although there are communications with the master station.

Regardless of which flavour is adopted, communication over the FAN is critical. If the FAN communication paths are broken or disrupted, FLISR will fail to restore power. To take full advantage of FLISR and other DA applications, power utilities need a FAN that can extend resilient, multiservice connectivity across the feeder domain.

Converged FAN: The foundation for a reliable grid

Utilities cannot feasibly connect all sectionalisers, controllers and switches along feeder circuits using traditional transmission assets such as fibre and microwave. Therefore, cellular wireless is the transmission medium of choice for supporting IEC 61850 communications in the distribution grid. However, utilities that rely on multiple DA applications need service convergence capabilities in the FAN.

An ideal FAN architecture is one that combines IP/MPLS services and cellular wireless connectivity to extend ultra-reliable wireless connectivity to the grid edge. This approach allows utilities to bring IP/MPLS services to utility poles and low-voltage substations that lack network reachability.

With a converged FAN, a utility gains the ability to connect IEDs, feeder circuits or DA subsystems to FLISR and other DA applications in the substation or operations centre. The converged FAN capitalises on IP/MPLS services to support IEC 61850 communications and carry data from FLISR and all other DA applications with the necessary quality of service.

The following figure shows a FAN blueprint that supports FLISR by enabling IEC 61850 communications between feeders and substations.

To provide the strong resiliency required to ensure that FLISR can continue to operate when accidents or weather events disrupt electricity services, the FAN must have a fully redundant end-to-end communication path. It must also have scalable, feature-rich IP/MPLS wireless routers that can capitalise on these capabilities.

Find out more

Explore our IEC 61850 resources to learn more about how the Nokia converged FAN can provide the resilient multiservice connectivity you need to support FLISR and other DA applications and use them to make your distribution grid more reliable, efficient and agile.

Join us at the 2023 UTC Telecom & Technology Conference in Fort Lauderdale, Florida, to learn more about taking IEC 61850 wireless. I will be speaking on this topic with my colleague, Rob Wright. We hope to see you there! 

About the author

Hansen Chan is an IP Product Marketing Manager with a special focus on digital industries and government. He has worked with telecom service providers and critical infrastructure network operators worldwide for more than 25 years on protocol testing, network design and consulting, and product management. When he’s not talking networks, he’s reading up on history and religion, and listening to Baroque and 20th century classical music.

Tweet him @hchan888