Closing the ‘last mile’ on distribution automation
The utility industry is evolving rapidly in size and complexity. Grid modernisation and new field services are underway to improve efficiency and productivity in a system with increasing penetration of intermittent renewable generation and small scale distributed energy resources.
In increasing numbers, advanced metering infrastructure (AMI), grid sensors, and distributed energy resources are being installed across the networks. Distribution automation enabled by these edge devices, is key for the system operator to maintain the grid’s integrity.
The challenge for grid modernisation is that it is a long term phased implementation utilising the technologies of the day. Commonly, technologies are based on a plethora of different standards – DLMS, G3-PLC, LTE, Wi-SUN to name a few – and backed by a slew of different types of communications networks from private to public and fibre to PLC to wireless.
Distribution automation
Multiple-use cases offer wide-ranging potential benefits for operational reliability, efficiency and system performance, as well as customer engagement and the enablement of prosumer participation in the market.
To increase safety, reliability, customer satisfaction and profitability, utilities are automating meter reads, power quality sensing and customer load profiles through automated two-way communication with the AMI.
Management of power quality throughout distribution systems is being automated with volt/var optimisation. Power restoration is automated with fault, location, isolation and service restoration (FLISR) technologies.
To integrate grids with other energy resources, distribution automation and the Internet of Things (IoT) is used to connect to distributed energy resources such as solar power generators, wind farms and microgrids.
Each of these energy resources has its own set of sensors and specialised substations, which are bringing growing volumes of data to manage and process both from their number and the read frequency as the grid management requirements have moved closer to real-time.
Utility Field Area Networking
This grid modernisation is driving intense focus in wireless Field Area Networking (FAN). Despite the aim for a single FAN, no one technology can support all of the use cases and utilities will have a variety of grid modernisation FANs, adding costs and complexities to their operations.
To simplify operations and to drive convergence within the FAN, new technologies pioneered by connectivity provider Cisco enable all of these technologies to be consolidated onto a single multi-service platform for monitoring and control of distribution networks.
The Cisco FAN solution includes technologies, products and architectures that provide new advantages in security, manageability, edge intelligence, scalability and high availability. This multi-service FAN includes a secure scalable network architecture leveraging LTE, Wi-SUN 900MHz mesh, LoRaWAN and wireline technologies all terminating in the same secure headend infrastructure.
The solution reduces complexity with unified management through the Cisco Field Network Director, which provides enhanced automation and serviceability via a zero-touch deployment and plug-and-play functionality.
With support for 10 million endpoints and a scalable headend architecture, the solution is designed to enable utility deployment of distribution automation assets at volume, speed and accuracy.
Jeffrey Tufts, Director of Global Energy Solutions at Cisco, says that there is the desire to consolidate on to one FAN technology and many projects start with this goal in mind. However, there is no silver bullet and often a FAN that was intended to be a single technology eventually grows to encompass several.
“Often a technology that supports line or pole sensors is not appropriate for real-time fault isolation use cases,” he points out.
“Cisco has worked to develop a utility FAN platform that can consolidate multiple FAN technologies into one architecture with a consistent operational model and security posture, allowing the utility to choose the right technology for the use case, geography or density while not taking on the burdensome task of supporting multiple disparate networks.”
FAN strategy
Tufts advises that a FAN strategy should support the widest array of use-cases across the utility’s operating territory with the fewest technology variations.
No single FAN technology choice can support all field use cases and utilities should converge as many use cases on as few FAN technologies as feasible. Reducing the number of unique FAN networks reduces the long term associated OpEx from support contracts, software licensing, frequency leasing and employee support costs.
A successful FAN strategy also should consider the immediate OpEx in addition to the long-term, he adds.
In the deployment phase for large-scale FANs, the onboarding of end-user equipment, FAN gateways and their corresponding power system devices is a major cost due to a large number of devices to be deployed.
Network automation has become the most adopted resolution to not only reduce deployment costs but also to eliminate human error and the OpEx associated with field remediation during Cisco’s installations.
Cybersecurity is increasingly becoming one of the most important business imperatives for utilities. Limiting the number of different FANs and architectures and their corresponding security postures reduces the cybersecurity complexity and further supports a reduction in the long-term OpEx.
Cisco’s FAN security architecture includes hardware and software certification management, firewall and malware protection and intrusion monitoring as well as robust encryption to help ensure secure network communications and edge applications.
Utility use cases
Public LTE and private mesh
In a lengthy proof of concept, one of the largest utilities in North America tested all 15 of its grid modernisation use cases and decided these could be best supported with a mix of public LTE, fibre and Wi-SUN mesh technologies from Cisco.
The utility’s architecture uses public LTE where it is available and where there is no public LTE service, it extends a private wireless network by using Cisco’s Wi-SUN standard mesh. Its entire grid modernisation architecture uses Cisco’s Distribution Automation platform to enable a single secure architecture that supports rapid technology deployment and a single management platform.
“We are seeing this scenario play out across the globe, where utilities begin their design and engineering phases with a preferred FAN technology but need to eventually adapt their FAN to encompass niche use cases that cannot be served by their primary FAN choice. It’s this adaptability to encompass multiple technologies in a single FAN that has been well received by our clients in the utility sector,” Tufts says.
Public and private LTE
Another leading large US utility has chosen Cisco to support its grid modernisation efforts via a combination of fibre, private LTE (pLTE) and public LTE. Similarly, the desire to be able to use the best technology for the use case, while consolidating on a single architecture and operational model, was the driver to this FAN architecture.
Tufts comments: “The adaptability of the Cisco FAN serves our pLTE FAN clients really well. Private LTE is growing in popularity, but it will take time to acquire frequency and build the pLTE network. Having a FAN that can be flexible to migrate from public LTE infrastructure, including frequency and SIM, to pLTE without truck rolls is an important project consideration allowing our clients to support grid modernisations with a platform that can be switched over to pLTE when desired.”
New edge technology
The emerging 5G with its high capacity, low latency characteristics is opening up a new world of connectivity of the Internet of Things. Capabilities such as network slicing are paving the way for innovative multi-service offerings via connected edge devices.
Utilities have started piloting 5G in distribution automation use cases such as substation monitoring and distributed energy resource optimisation and the technology is expected to be key to support the next wave of smart grid growth at the medium voltage level.
In anticipation of these and other advances including the emergence of Wi-Fi 6, Cisco has recently launched a new portfolio of industrial gateways and routers to unify these technologies into the FAN.
Read more on: Connecting the modern grid: Agility is more important than ever
These ‘Unite your edge’ devices, which were conceived with flexibility and scalability in mind, are intended for fixed and mobile installation in locations such as substations, poles and maintenance trucks. They are modular in design for easy installation with a rugged build to withstand the harshest environments and include built-in edge compute resources along with advanced security features such as hardware encryption.
“With the latest releases of our industrial platforms, we have introduced a level of performance, security, modularity and future adaptability unseen before in the industry,” Tufts concludes.
“We hope that this continues to serve our utility clients well as it protects their investments from obsolescence and enables a platform approach that can be adapted as new technologies such as 5G emerge.”
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