Product Application: New system helps university manage power

In the early 1990s, a power failure at Stanford University meant hours of waiting for electrical crews to trade phone calls and search all possible problem spots. But that was too slow for a multifaceted campus the size of a city. The university has 46 miles of roads, a 50 MW power plant, two separate water systems, three dams and lakes, 100 miles of water mains, a central heating and cooling plant, a 70-acre shopping complex and a medical center.

The engineers and electricians of Stanford Utilities, a division of Stanford, needed a better way to manage the power-distribution system. They had to fully understand the condition of the electrical system at all times in order to minimize disruptions. If they could automatically gather data from the entire campus, they could quickly locate faults, analyze power quality, track energy usage, and prevent outages from happening in the first place.

The answer was a Supervisory Control and Data Acquisition (SCADA) system. After reviewing several options, Stanford Utilities chose one from Power Measurement.

"Before installing our SCADA system, the best way we could react to a power failure was through a combination of waiting, hoping, guessing, triangulation and luck," says Tom Gilligan, an electrician specialist at Stanford.

It would start with a call from a building manager reporting a loss in power. Not knowing which branch of the circuit had failed, electricians stood around the shop waiting for more calls from other affected areas. Slowly, they were able to target a specific section of the circuit and dispatch high-voltage crews along the routes of underground distribution cables. The crews then had to remove vault and manhole covers to reach fault indicators and finally zero in on the source of the outage.

That's all changed. Now, utility system operators can remotely identify the source and extent of power failures anywhere in the electrical distribution system. With real-time data and alarms, they can quickly locate the problem and instantly respond to questions and concerns from building managers, researchers and department chairs. They also can minimize the chance of recurrence by studying historical information and making corrections.

The status of every campus emergency generator is indicated by its breaker and transfer switch positions. Instead of technicians performing weekly checks of those positions, digital power meters continually monitor them and immediately report malfunctions.

"We've configured the SCADA system to automatically gather data from feeders, breakers, transfer switches and transformers across the campus." explains Gilligan.