High-voltage generation reserves cost more than would portable, small-scale units to keep critical services on line during a major power outage.
Grid, Heal Thyself
Automation technologies promise a reliability revolution.
speaking, there are several synonymous acronyms for self-healing applications, including fault location, isolation, and service restoration (FLISR), and fault detection, isolation, and service restoration (FDIR). Both are shorthand for applications that, like the smart- grid systems that envelop them, will mean different things to different utilities. Implementation must take into account climates, demand, population densities, and the way distribution already is organized. Advanced self-healing is tied to distribution management systems (DMS), including on-line power flow, switch order management, optimized feeder reconfiguration, and supervisory control and data acquisition systems (SCADA).
Despite all the technology jargon, however, the self-healing grid is simple at its root, says Kevin Cornish, an executive consultant at Enspiria Solutions, which offers smart-grid strategy, business, and integration consulting services to utilities. “We’re taking a system that was designed to be radial and now we’re going to operate it in a way that makes it much more interconnected, much more networked,” Cornish says. Such upgrades can have system-wide implications—and as a result, many utilities are taking a gradual approach to adopting self-healing technology.
“Some utilities have a big appetite for big bang—they’ll do everything and they’ll be really aggressive,” says Mike Edmonds, vice president and general manager of Siemens Energy’s power distribution energy automation business. “Others are a little more conservative. They may want to start from a control center level, spool in some microgrids, and maybe connect them together.”
Spurred by DOE smart-grid investment grants that were awarded last fall, utilities throughout the country now are planning pilot-scale demonstrations that include self-healing applications. The projects, which combine a range of advanced outage management technologies, are as diverse as the utilities involved.
For example, to harden its grid against inevitable tropical storms, CenterPoint Energy is first deploying an end-to-end advanced metering system that will gather real-time data. Since the Public Utility Commission of Texas approved CenterPoint’s five-year metering plan in December 2008, the utility has been rapidly installing digital meters, a communication network, and back office systems. A grant from the DOE shortened the project’s timeline so that every one of its customers is expected to be connected to the AMI system by mid to late 2012.
Once that phase of the project is complete, CenterPoint plans to install new line devices along the system the same way it has been deploying the metering devices. They include line sensors, switches, and microprocessor-controlled electronic devices that can relay data. Simultaneously, the utility will be installing its advanced distribution management system, ADMS, so that the devices communicate at the same frequency as the meters.
“Our ADMS system will be the brains,” Mercado says. “It will have the intelligence to take outage, legacy, and customer information, bring it all together, and create the algorithms that enable the self-healing and functional benefits we expect to deliver to customers with the smart grid.”
Further east, in the Carolinas, Progress Energy already has capabilities that some utilities might envy. When there’s a breaker lockout in its service territory, its SCADA system can locate the fault within two poles 80 percent of the time, says Becky Harrison, general