Is your distribution grid ready for the new age of electricity?
The movement to electrify everything is accelerating as businesses, governments and people shift away from carbon-based energy and embrace fully electric homes, buildings, transportation and industrial processes.
Power generation is also changing fast as the energy industry deepens its investments in distributed energy resources (DERs) such as wind turbines, solar panels and battery storage systems. These resources come with new challenges that will compel distribution system operators (DSOs) to make the grid more flexible and dynamic. The “duck curve” phenomenon exemplifies these challenges, illustrating the mismatch between peak solar generation during daylight hours and peak power demand in the late afternoon and evening.
So what is a forward-looking DSO to do about all this change? The key to success is to deploy automation and other modern technologies that will ensure that the grid can smoothly integrate DERs and deliver on growing power demands. To make these technologies pay off, DSOs will need to crank up the capabilities of their field area networks (FANs).
Distribution automation depends on IEC 61850
Distribution automation (DA) technology will play a vital part in helping DSOs address emerging challenges and opportunities. One of its pillars is IEC 61850, a standard family that provides an interoperability framework for the data exchanges that drive DA applications.
Introduced 20 years ago with a focus on substation automation, IEC 61850 now supports DA applications across the grid. It offers a standardized way to model data, which enables feeder domain devices to exchange critical information in real time. IEC 61850 also defines a common language for device descriptions and configurations, which makes it easier to integrate new devices into automated substations.
FANs need an upgrade for IEC 61850
IEC 61850 needs a solid connectivity foundation to support advanced DA applications. The FAN carries IEC 61850 data across the grid and performs the crucial job of connecting feeder circuit domains and low-voltage distribution substations.
But many existing FANs aren’t ready to help drive grid transformation. Factors such as climate change and the growing use of heat pumps, EVs, home batteries and solar panels will soon highlight the limitations of existing FANs in the distribution domain. DSOs will need DA to keep up, and they’ll need an agile communication infrastructure to support it. The solution is to upgrade to converged multiservice FANs that will ensure that they get full value from new grid technologies and use cases such as DA applications.
How can a converged multiservice FAN help? By integrating an IP/Multiprotocol Label Switching (IP/MPLS) field router with a wireless (LTE) or fiber (GPON) network to connect a multitude of devices, from intelligent electronic devices (IEDs) such as reclosers and line switches to CCTV cameras and drones.
Figure 1: A converged FAN blueprint for DA applications
Many DSOs already rely on fiber and IP/MPLS networks, but many grid assets remain unconnected. A converged FAN can provide the connectivity foundation for bringing DA to substations, DER sites, utility poles and more. It can also connect the masses of IEDs along feeder circuits and provide backup connectivity if a fiber cut occurs.
Converged FANs that extend IP/MPLS over LTE can enable DSOs to meet the stringent performance requirements of grid monitoring, control and security applications, which include low latency, service aggregation, high availability and strong resilience. The convergence of wireless, optics and IP will support a diverse range of DA applications that help DSOs achieve new levels of efficiency and reliability.
Automation makes grids more reliable
The consequences of service interruptions are growing as more industrial, transportation and public works applications run on electricity. Among the many DA applications enabled by converged FANs, fault location, isolation and service restoration (FLISR) stands out as an essential use case for avoiding interruptions.
FLISR systems work with line sensors, distribution management systems (DMSs) and outage management systems (OMSs) to locate faults, open line switches and isolate the affected sections of the grid. They then automatically reroute power to downstream users by connecting them with an alternative substation. According to the US Department of Energy, FLISR can reduce the number of customers interrupted (CI) by 55% and customer minutes of interruption (CMI) by 53%.
A converged FAN makes FLISR applications work by ensuring interruption-free communication with line sensors. This continuous communication also enables FLISR subsystems to make automated adjustments, such as the use of advanced distribution management systems (ADMSs) and volt/VAR optimization (VVO) to maintain voltage levels and avoid brownouts and equipment failure.
DSOs can achieve continuous communication and service continuity with a converged FAN that features a fully redundant end-to-end wireless communication path. In this scenario, a dual-homing wireless field router seamlessly switches communication to a secondary wireless circuit if the primary circuit fails. Robust multi-fault resiliency in the FAN backhaul intelligently reroutes affected paths to maintain communications with the wireless core software in the data center.
FAN convergence helps prevent islanding
As DSOs integrate more solar panels and home batteries into the grid, they need DER islanding prevention measures that go beyond open reclosers adjacent to fault locations. For example, if a solar array inverter doesn’t recognize that a DER island has been formed, it may keep supplying power to feeders downstream from the recloser through the point of common coupling (PCC).
With a converged FAN, control logic can send a trip command to the downstream switch at the PCC to prevent the inverter from supplying power to the feeder. This measure keeps field crews safe and ensures that the local grid infrastructure can reliably perform its critical functions.
Automation enhances fire mitigation, too
As climate change accelerates, many regions face higher temperatures, prolonged droughts and more intense winds. Fire mitigation is an essential use case for DSOs in these regions. Every DSO wants to avoid triggering wildfires to maintain safe operations. They also want to avoid the stiff financial penalties levied on DSOs that cause wildfires.
For most DSOs, the primary fire mitigation strategy is to proactively maintain equipment and vegetation in distribution corridors. Fallen trees that bring down conductors are a leading cause of electrical wildfires. Tree branches and other forms of vegetation that come into contact with power lines can cause arcs and sparks, as can failures of aging grid equipment.
DSOs can use DA to complement these proactive maintenance efforts and enhance fire prevention. For instance, DA applications can rapidly detect fallen conductors and trip power, or sense breaks and cut power before the conductor hits the ground. But detection of high impedance faults (HIFs) is challenging, and protection systems aren’t always triggered. Some DSOs choose to close high-risk lines and route around affected areas instead, but this approach can extend power restoration times.
A California utility addresses the HIF detection challenge with a technology that monitors synchrophasor measurements for voltage, current and phase angle across all conductors on a power line. The technology feeds the data to an automation controller that looks for HIF signatures. When it detects an HIF, the controller sends an IEC 61850 GOOSE message to trip the power on the line.
To implement this technology, DSOs need to support high-bandwidth, low-latency communications so that the solution can gather phasor data, detect anomalies in real time and send GOOSE messages to circuit breakers and reclosers. The FANs must deliver consistently low latency and jitter. Converged FANs that use IP/MPLS over optical fiber backhaul can meet all these criteria.
Why it’s time for converged multiservice FANs
DSOs have traditionally relied on a set of specialized FANs to connect IEDs such as line switches, voltage regulators and SCADA remote terminal units (RTUs). Each of these FANs requires its own cabling, power, FAN management and more. Now that DSOs are embracing DA systems and building smarter grids, this traditional approach is too expensive and hard to scale.
A converged FAN built on IP/MPLS over fiber or wireless clears the path to grid transformation because it can scale easily and support multiple services concurrently. It provides a robust communications foundation for emerging native IP applications, such as Layer 3 VPNs for synchrophasor, as well as layer 2 applications such as GOOSE and Sampled Values (SV). With a converged FAN, a DSO can avoid the cost of powering, managing and multiple FANs and deploy new IEC 61850-based DA applications.
As artificial intelligence (AI) emerges as a transformative force across industries, DSOs are actively exploring and evaluating its potential. A converged FAN is a key enabler for DSOs seeking to harness AI’s power. It facilitates AI adoption by efficiently backhauling operational data, environmental information such as weather data, and other relevant metrics to AI-assisted IEC 61850 applications located at substations or data centers so they can process and act on it. By deploying a converged FAN, DSOs gain a foundation for using AI-driven insights to make faster decisions, enhance grid operations and maintenance, and improve overall operational efficiency.
As DSOs evolve their grids to meet the demands of the electrification movement and integrate renewable energy sources, a key pillar has emerged—the converged multiservice FAN. By upgrading to converged FANs that take advantage of the latest advances in IP, fiber and wireless networking, DSOs will be able to use an array of DA applications to ensure seamless and secure grid operations for the new age of electricity.
More to explore
Read our article in Energy Central to find out more about how a converged FAN that combines IP/MPLS and LTE can support the IEC 61850 communications required for FLISR and other advanced DA applications.