by Scott Koehler, Telvent Utilities Group
As advanced metering infrastructure (AMI) deployments continue to expand, the industry is looking for ways to integrate with other solutions to maximize the return on investment. The combination of AMI and meter data management (MDM) is a common example of how utilities are interfacing AMI with other systems to achieve data sharing and interoperability. The MDM validates, edits and estimates meter readings, streamlines billing processes and supports beneficial rate designs and time-of-use programs.
To create a truly smarter grid, however, the industry must consider broader system integration for AMI to capitalize on the wealth of information and advanced capabilities it provides. One increasingly popular approach is to use AMI to improve operations via integration with an outage management system (OMS).
An OMS traditionally relies on customer calls to identify outages and predict their locations. But with AMI, an OMS can provide operational intelligence that neither system offers independently. Together, AMI and OMS can reduce outage times, improve outage detection and provide more efficient crew management and more accurate reliability reporting. Even momentary events that might not require a response can be analyzed to help mitigate issues and optimize information shared with regulators, customers and others.
The following outlines what a utility should consider to integrate AMI with OMS and the tangible outage management advantages that extending AMI to the control room makes possible.
An OMS that meets open-standards interoperability, including testing to the IEC 61968 standards, is the surest way to ease deployment and maintenance and avoid obsolescence. Performance criteria testing will determine whether the OMS will process tens to hundreds of thousands of events per hour reliably and manage large-scale outages without impairing the work flow of dispatchers and operators. Finally, an OMS with a services-oriented architecture, such as Web services, allows for scalability and enhancements as a utility expands AMI in the enterprise.
Better Tools for a More Reliable Grid
Integrating AMI with OMS functions results in faster responses and power restoration. The following are the most business-critical advantages for electric utilities:
Validate outages for more efficient response. AMI communication systems generally are reliable, but message collision and AMI network bandwidth constraints can prevent "no power" messages from reaching the OMS. Some AMI systems also might deliver duplicate and out-of-order messages. An OMS with a robust integration infrastructure can filter all unnecessary AMI event messages to avoid overburdening the core analysis engine.
OMS and AMI integration allows for automatic or manual pinging of meters. The response time of a ping request varies, but utilities using this functionality can experience significant time and cost savings by validating events, eliminating unnecessary truck rolls and consequently making more efficient use of crews.
In addition to restoring customers' power faster, many utilities find it valuable to proactively communicate power problems, crew status and estimated restoration time to customers. Regardless of the communication medium, a utility can notify a customer that the utility knows of a power problem in their area based on an AMI report.
Find outage events faster. Utilities that rely on customers to report outage events face challenges including the ability to react quickly and accurately with limited information. On average, only some 10 percent of customers call to report power problems; notification rates varying depending on the time, day of the week and location.
In contrast, the AMI's ability to communicate "no power" events to the OMS means more immediate and reliable data, which increases the OMS' ability to identify problem locations and provide visualization and analysis of the affected area. As AMI gathers and sends data, the OMS processes and analyzes it using the tracing and prediction analysis functions of a real-time distribution network model to determine the affected protective device.
An AMI could not do this alone; the topologies of its communication systems have limited knowledge of the power distribution network beyond the relationship of a meter to a customer premise or other discrete locations. But by leveraging a utility's geographic information system (GIS) as-built model, the OMS can maintain the as-operated state of the network accurately and provide users with a geospatial model and view of network activity. This results in more reliable incident-location identification for field crews and a faster response to alleviate the issue.
AMI solutions also can communicate notifications from devices higher on the network, such as collectors, giving the OMS additional data for prioritizing events and identifying incident locations more rapidly. Similarly, reports of partial power and power quality-related events help the OMS provide improved management of unplanned and planned events.
Faster service restoration. Nested outages during restoration can be difficult to identify. Pinging suspect meters downstream from the primary restoration event can help identify residual or nested outages resulting from multiple faults downstream of a protective device. The OMS can create new incidents for these nested outages while crews are on-site, eliminating associated customer callbacks, redundant truck rolls and extended outages.
Accurate Performance Information
Utilities benefit from operational improvements, and AMI-OMS integration also helps manage critical documentation of event management and restoration times. More accurate historical data leads to: improved quality of reports; reliability indexes such as the Customer Average Interruption Duration Index (CAIDI), System Average Interruption Duration Index (SAIDI), Customer Average Interruption Frequency Index (CAIFI), System Average Interruption Frequency Index (SAIFI) and Momentary Average Interruption Frequency Index (MAIFI); and other analyses shared with management, regulators, customers and the media.
As the world depends more on a reliable electrical grid, power distributors will continue to be challenged to improve outage management strategies. AMI provides the data to enhance the resolution of outage events provided by OMS and enables utilities to respond faster and more effectively to network events. This synergy between information technology systems is part of an important trend of systems integration for utilities, bringing the capabilities of multiple systems together in a powerful suite to improve customer service, decrease operational costs and make the smart grid even smarter.
Scott Koehler is director of smart grid management at Telvent Utilities Group. He is an electrical engineer with 20 years of combined utility, software and system integration experience.
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