Electric power quality disturbances such as transients, voltage sags and dips cost the U.S. economy $15 billion to $24 billion per year, according to research funded by the Electric Power Research Institute. When power disturbances occur, data can be lost, equipment can be damaged, and processes interrupted, sometimes leading to costly downtime.
One case in point involves Argonne National Laboratory, Argonne, Ill.—a U.S. Department of Energy (DOE) facility managed by the University of Chicago. At Argonne, the negative impact of power quality disturbances is today better understood than in the past, thanks to an enterprise energy management (EEM) system installed to monitor power at the facility’s 1,500-acre campus. The EEM system has enabled Argonne to pinpoint the source of some costly power quality problems that were impacting sensitive scientific equipment, says Jim Heine, Argonne manager of utility systems. As a result, he says, the facility has been able to take steps to head off future recurrences—saving perhaps millions of dollars in the process.
Toast and Science
Small power glitches and power sags “might not affect some guy with his toaster at home,” Heine quips. “But out here, with this scientific equipment, it makes a difference.”
The Argonne campus houses some 100 buildings dedicated to federally funded scientific research and development. Facilities include the Advanced Photon Source, or APS—a 1,104-meter circumference accelerator complex that houses numerous machines and devices used to produce, accelerate and store a beam of subatomic electrons, providing the Western Hemisphere’s most brilliant X-rays available for scientific research. Electrical power for the Argonne campus is supplied at the 138 Kilovolt level, and the DOE facility maintains its own electrical substations and distribution system for delivering that power throughout the campus.
As a way to better control energy-related costs and improve the reliability of its power, Argonne in 2003 began installation of an ION EEM system supplied by Power Measurement, of Victoria, British Columbia, Canada. Power Measurement was acquired by Schneider Electric in April 2005, and is now part of Schneider’s power monitoring and control group.
The ION energy management system uses a network of advanced energy meters installed at power mains, substations and feeders to monitor the electricity supplied to the Argonne campus. The system is being installed in phases; a third phase is currently underway, says Mike Burns, a Chicago-based business development specialist for Schneider’s Square D PowerLogic operation. In the first two phases, which ended last year, about 70 ION energy meters were installed at Argonne, providing campus-wide coverage, says Burns. The third phase will provide additional monitoring capability for an underground switching ring that serves a section of the Argonne campus.
The ION 7600 and ION 7350 meters installed at Argonne collect data on power quality, energy consumption and breaker status throughout the campus distribution system. That information is relayed via Argonne’s fiber optic network to a centrally located workstation equipped with ION enterprise energy management software.
More Data
Compared to an older supervisory control and data acquisition (SCADA) system that Argonne had used previously for power monitoring, the ION EEM system is not only easier to use and more reliable, but it also provides much more information, says Tom Secor, Argonne electrical distribution foreman. The Microsoft Windows-based ION system server is located in Argonne’s continuously manned “boiler house,” and provides a graphical user interface showing a map of the Argonne site. Operators can click on any of the substations, meters or equipment on the map display to drill down for more detailed information, says Secor.
An alarm system enables quick pinpointing of problems for rapid dispatch of maintenance or repair personnel. The system enables continuous tracking of energy usage by facility, and provides real-time status information on breakers and other equipment, while storing all information in an historical database.
Unlike Argonne’s previous system, the ION EEM system captures and stores electrical waveforms, which helps greatly in troubleshooting, Secor says. “When the voltage dips, it can affect a lot of facilities on site, and we can go back and see how much the voltage dropped and how much the current went up, and trace it through the different meters so we can see what actually caused it,” he explains.
It was that capability, in fact, that enabled Argonne to discover the source of some power problems last year that were causing power-sensitive equipment at the APS to shut down unexpectedly, affecting ongoing scientific research. “I think we had four or five shutdowns,” says one Argonne engineer, who puts the cost at about $20,000 per hour, with shutdowns ranging from a few hours to more than 24 hours.
Problem Tracing
By using the ION EEM system, according to Heine, Argonne was able to trace the cause of the shutdowns to voltage sags coming from Commonwealth Edison, which delivers electrical power to the facility. “Before we had this energy management system, we would not have known,” Heine says.
Once the source of the problems was pinpointed, Argonne was able to meet with utility officials “to sensitize them to what was going on,” says Heine. “Prior to that, they didn’t realize how sensitive our equipment was.” Commonwealth Edison was then able to “schedule some of its maintenance so it would not interfere with our operations,” says Heine. The utility also recommended that Argonne take steps to protect the sensitive APS equipment. APS personnel subsequently installed some uninteruptible power supply (UPS) equipment at the research facility, Heine says. The combination of actions taken by Commonwealth Edison and by Argonne now appears to have mitigated the problems with the power-sensitive APS equipment, he concludes.
Going forward, Argonne plans to make broader use of the ION EEM system capabilities for better energy cost management, Heine says. In order to obtain the most favorable utility rate charges, Argonne must maintain its power consumption within a 30 percent bandwidth in winter and a 10 percent bandwidth during heavy-demand summer months, Heine explains. “If we exceed that, we get nailed with some extra costs.”
So by using the EEM system to closely track and assess its power usage, Argonne may be able to take steps when needed to avoid excess charges. “As the price of power just keeps going up and up, the more information we have coming in to us, the better off we’re going to be, and the better we’ll be able to manage our facility,” Heine observes.
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