Despite offering a range of benefits, microgrids are proving to be controversial—especially when non-utility owned microgrids seek to serve multiple customers. The biggest battles are taking place...
Grid, Heal Thyself
Automation technologies promise a reliability revolution.
manager of the utility’s smart- grid program. With help from a DOE grant, Progress Energy’s distribution system deman-response (DSDR) initiative includes plans to refine its fault-locating capabilities, add reclosers, and automate them so they can be operated remotely. “We’re overlaying the power grid with an information and control system,” Harrison says.
And to the west, in Boulder, Colo., Xcel Energy’s SmartGridCity project has become a proving ground for system-wide changes. “They’re doing a huge push to apply technology in every way—from the meter to the feeder to the substation—everything they can do to make power more reliable, more controllable, and more responsive to the consumers all the way down,” says Roy Moxley, R&D marketing manager for Schweitzer Engineering Labs protection group. SEL is among the project’s multiple vendors.
SmartGridCity is testing numerous technologies and processes that will make its grid self-healing, says Randy Huston, program delivery executive for Xcel. That includes adding new processing and monitoring capabilities to four main substations, reconfiguring key feeders, as well as adding distribution transformer monitoring and underground fault detection.
“We selected goals that were a significant stretch but still achievable,” Huston says. “For example, we didn’t try to modify all of the feeders to the segment model but only the number needed to obtain the data we were looking for.”
The major challenges to adopting advanced self-healing grid applications don’t necessarily stem from a lack of available technology. DMS vendors say the technical components already exist. The problem seems to be getting to the point where utilities can integrate them into intelligent systems and then comfortably rely on the processes to work smoothly and safely.
To put advanced self-healing grid systems in perspective, last year some utilities still were using paper maps, says Gary Rackliffe, vice president of smart grids for ABB in North America, which produces smart grid relays, reclosers and switches, as well as logic for automatic fault restoration. “Going from paper maps to saying, ‘I’m going to sit here and watch the computer make the decision and start throwing switches’—that’s a significant leap forward,” he says.
For utilities in the early stages of smart-grid demonstration projects, it makes sense to have concerns about taking the next step. Vendors argue that current data limitations should motivate utilities to come up with solutions, rather than allowing those limitations to paralyze them. Jonathan Piel, product director for substation and distribution automation at Cooper Power Systems, says that some decentralized approaches have made it hard for utilities to determine whether their plans will work the way they intend them to.
“I fear that utilities are still stuck in a pilot mentality for self-healing grid,” Piel says. “There’s a series of problems that don’t engender confidence for utilities, so they are piloting it to death.” One way to foster greater confidence, he suggests, is to use simulation tools that allow the utility to run constant what-if scenarios.
In a self-healing grid, tasks that were automated by a human SCADA operator who communicated via radio with line workers will be done automatically without any human involvement. Relinquishing