by Tom Ayers, Tropos Networks
We’ve seen announcements in the past 18 months about smart meter project deployments. I call this Smart Grid 1.0. As we enter 2011, utilities are developing their Smart Grid 2.0 strategies.
What is Smart Grid 2.0? It’s about distribution grid management automation, which is central to smart grid as a self-healing, digitally controlled network for reliable electric power delivery. Distribution automation (DA) is the fastest-growing smart grid segment. As real-time, mission-critical applications, DA requires a robust, two-way, low-latency and high-bandwidth communications infrastructure. Wireless is the only cost-effective way to provide connectivity to millions of endpoints dispersed throughout the distribution system. Legacy technologies based on proprietary and narrowband radio technologies will not meet DA application requirements. Needed are highly reliable, high-performance (lower-latency and higher-bandwidth) networks based on open standards that can deliver on DA mission-critical requirements while laying a communications infrastructure foundation for other current and future smart grid applications.
DA has been around since the 1960s, but recent advances in information and communications technologies enable a broader DA vision to be realized. With the advent of lower-cost, wide-area communications, it becomes feasible to extend visibility and automation further into the distribution system to devices and endpoints on feeders and into homes. Devices such as capacitor banks or thermostats are transformed into communicating endpoints that actively can be monitored and controlled. Embedded intelligence at DA endpoints enables distributed protection and control applications.
DA is receiving fresh impetus from regulatory mandates, increased emphasis on power quality and reliability and the emerging need to address plug-in electric vehicles and distributed generation integration. DA provides utilities key, quantifiable benefits, the most important of which is ensuring service quality and reliability, energy conservation and improved asset utilization. It will enable utilities to optimize electricity delivery and accomplish environmental and energy conservation goals while delivering high service reliability and quality by reducing outages and speeding restoration.
Unlike less demanding applications such as advanced metering infrastructure (AMI), DA imposes fairly stringent performance requirements on the underlying communications infrastructure. Because it is a mission-critical application, the communications network must have 99.999 percent availability and very low failure rates under normal operating conditions; and high survivability, the ability to withstand unexpected or infrequent events such as extreme weather events. It also must securely transport of mission-critical data and protect the communicating devices on the grid from would-be hackers. The network must reliably provide very low latency end-to-end communication, as low as 20 milliseconds for delay-sensitive DA applications such as protection and control systems. It also must have sufficient capacity (multiple megabits per second) to support the simultaneous communications needs of many endpoint devices from transformers to reclosers and capacitor banks.
These are challenging requirements, especially for wireless communications prone to failures and variations in radio frequency (RF) propagation. Driven in part by the need to meet these requirements for DA and other smart grid applications, the utility communications landscape is evolving rapidly away from legacy approaches using proprietary, single-purpose, narrowband RF technologies toward higher-performance, standards-based, multipurpose networks.
As utilities migrate from Smart Grid 1.0 to Smart Grid 2.0, many legacy application-specific radio technologies that have supported applications such AMI will be hard-pressed to meet DA bandwidth, latency and reliability requirements. Open standard radio technologies such as IEEE 802.11 and 802.16 will best deliver the robust broadband backbone communications infrastructure the next-generation smart grid will be based.
Tom Ayers is CEO of Tropos Networks.
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