By Fai Lam, Nokia
Managing an electrical power grid is all about balance. Electric utilities must balance the demand from residential and commercial customers with generation and supply processes and capacity 24/7/365. At the same time, they must balance reliability, performance and cost to meet operations objectives and customer expectations in real-time for always-on electricity. This ongoing balancing act is becoming more complex. In addition to managing operations to maintain that delicate balance, electric utilities face new challenges. Green environmental regulations, the growing adoption of disruptive energy technologies and changing electricity consumption patterns are pressuring utilities to modernize their distribution systems. Underpinning these modernization efforts is a shift in the communications technologies used in field area networks (FAN).
Understanding the Challenges of Today’s FANs
FANs give utilities more oversight and control over the electricity they distribute. They allow utilities to optimize operation and production processes by increasing grid responsiveness, which can substantially improve efficiency and reduce costs. By connecting intelligent electronic devices (IEDs), for example, FANs allow utilities to monitor voltage levels, restore them in real-time and understand energy demand patterns. IEDs also can exchange control signals, such as trip/close commands, to protect the grid and restore electricity flow when necessary. These abilities are crucial to operating a reliable and efficient power grid that maintains the right balance between supply and demand, reliability and performance, and ultimately bring cost savings to both utilities and customers.
FANs play a crucial role in grid operations. The way they have been deployed to date, however, complicates further grid modernization efforts. To support different grid applications, some utilities have deployed multiple FANs (Figure 1). For example, an electric utility may have one FAN for advanced metering infrastructure, another for line monitoring and a third for protection. Each FAN is typically based on different networking technologies and requires its own specific maintenance and support processes.
This segregated approach to FAN deployment means that many utilities now have multiple discrete communication networks that must be managed and maintained separately. This creates higher operational and maintenance costs and hampers control, coordination and communications between various grid applications. It becomes a barrier to application integration and thus stalls future innovations.
In addition, this approach cannot scale cost effectively. As applications become more intelligent and require data from each segregated FAN, the volume and mix of grid information that must be collected, processed and exchanged will increase significantly. The underlying communications networking technologies that enable existing FANs, however, have limitations that will not allow utilities to attain consistent operations and efficiency. In most cases, they cannot support the data tsunami that must move through the network to enable intelligent operations. They also cannot provide efficient peer-to-peer communications, which is essential for adoption of distributed intelligence paradigms. They may, in fact, become a choke point in intelligent grid communication.
|FIGURE 1: Distributed FAN Networks|
This situation exists for a variety of reasons:
“- Some technologies, such as analog phone lines and leased circuits, are becoming obsolete.
“- Some wireless network technologies, such as IEEE 802.15.4g (commonly known as ZigBee), are narrowband with limited bandwidth, making them adequate for reading meter data, but not for other applications such as intelligent distribution automation.
“- Some wireless technologies, such as point-to-point and multipoint microwave, need line of sight, which requires extensive RF link design and hinders a utility’s ability to move and add new field devices. They also are typically proprietary, which might limit the technology’s forward evolution path.
“- Some wireless technologies use unlicensed spectrum, which is vulnerable to interference.
“- Other wireless technologies, such as WiMAX, have limited telecommunications industry acceptance, resulting in a small ecosystem and limited economies of scale.
Building Intelligent Automation with a Converged FAN
Although the challenges are significant, a solution is available. Converged FANs that are built on broadband technology might be the key to intelligent distribution automation and efficient operations. A converged FAN that leverages broadband provides reliable, secure and scalable managed communications to consolidate current grid applications, as well as abundant flexibility and capacity to grow. Power utilities, therefore, can provide better services to customers and integrate green energy seamlessly while maintaining a balance between supply and demand, reliability, performance and cost. The optimal approach is to build converged FANs that are based on services built on internet protocol/multi-protocol label switching (IP/MPLS) and long term evolution (LTE) wireless technologies.
Why These Technologies?
IP/MPLS technology merged with LTE provides a powerful and versatile approach to FAN deployments built for today and the future.
Many utilities worldwide have deployed IP/MPLS to build their mission-critical wide area networks (WANs). By extending Layer 2 and Layer 3 IP/MPLS services from the WAN to the FAN, utilities also can leverage the same technology used in the WAN. Using the same network manager, utilities can bring highly-scalable, secure, end-to-end managed MPLS services and reliable data transport with high quality of service (QoS) to the distribution grid. In addition, individual applications can be bound to their own specific Layer 2 or 3 MPLS service that provides flexible interconnectivity to field devices in the FAN and control and management system in operations centers.
LTE has been deployed by most mobile carriers globally. It provides the bandwidth, speed and reliability to support the ever-accelerating volume of voice and data traffic generated by smartphones, tablets, laptops and other smart devices. Its low latency and high throughput makes it ideal for peer-to-peer communications in machine-to-machine and Internet of Things distributed intelligent applications. It can connect FAN devices together with proven security and reliability.
LTE provides the economies of scale and wide ecosystem that enable cost-effective deployment and ongoing network maintenance. Its flexible channel size allows it to cater to different bandwidth requirements, ranging from hundreds of megabits per second to tens of kilobits per second. In addition, its advanced QoS capabilities enable utilities to provide specific QoS levels to different applications.
LTE deployed in the FAN also can be leveraged for the increasing communication demands of power utilities’ mobile workforces. Installers and operations personnel traveling to remote sites can use the LTE-based FAN deployments to connect their tablets and laptops to the FAN. This allows utilities to make the most use of their converged FAN investment.
Another benefit for utilities is that LTE does not require line-of-sight. This means that a FAN built with LTE allows utilities to extend a grid communications network rapidly with the necessary bandwidth and QoS for intelligent operations. Its flexibility also allows utilities to add and move field devices as needed. Finally, since LTE is an IP-based wireless technology, the LTE backhaul network will fit seamlessly into the mission-critical WAN.
By moving to a converged FAN grounded in LTE and IP/MPLS, electric utilities can create a scalable, managed broadband network that provides secure, reliable connectivity for all grid applications (Figure 2). This enables utilities to address all distribution connectivity requirements with a single communications infrastructure.
|FIGURE 2: Converged FAN Architecture for Segregated, Secure, Application-specific Communications|
Creating Operational Balance with a Converged FAN
Ultimately, a converged FAN built with IP/MPLS and LTE is a foundation to utility grid modernization efforts. Optimized for anywhere-to-everywhere communications, it allows utilities to support a multitude of grid applications with secure, reliable broadband connectivity inside the FAN, and bridge the gap between the FAN and WAN. This makes it easier to provide end-to-end communications between field devices, distribution substations, transmission, generation and operations centers. It enables true intelligent operations and improves power reliability and quality. Moving forward, a converged FAN can also play an integral role in bringing utilities into the Internet of Things era.
Fai Lam is marketing director for IP/Optical Networks at Nokia. He is a seasoned professional in networking and communications technology and has helped industries, such as power utilities, with their transformation projects. He has held positions in product development, product line management, business development and marketing. Fai holds a bachelor’s degree in electrical engineering from the University of Victoria in British Columbia, an MBA from the University of Ottawa and is a registered Professional Engineer in Ontario, Canada.