Situational awareness requires data visualization tools
PJM Interconnection and SDG&E share their favorites
Published In: Intelligent Utility Magazine March/April 2011
EVERYTHING COMES DOWN TO DATA: ITS AVAILABILITY, ITS reliability, and the ability to be able to monitor and control everything from electricity flow and metering data to utility enterprise management information, costs, budgets and rates.
And now, there are computerized dashboards for all of it. From distribution and transmission operation control rooms to customer billing systems and more, data flow from numerous sources is optimized via software solutions to provide the information necessary to operate today's up-to-the-moment utility functions.
Add geographic information system (GIS), supervisory control and data acquisition (SCADA) and phasor measurement units (PMUs) to Google Earth, WeatherBug and more, and the internal and external data available to electric utilities is diverse. Utilities are leveraging these new and not-so-new tools to assist them in visualizing the big picture.
PJM uses PMUs for situational status
Data visualization is playing an ever-growing role in a utility's day-to-day and hour-to-hour functions. For PJM Interconnection LLC, visualization tools play an important part in the role it plays as a regional transmission organization (RTO) that is responsible for managing the high-voltage electric grid and the wholesale electricity market that serves all or parts of Delaware, Illinois, Indiana, Kentucky, Maryland, Michigan, New Jersey, North Carolina, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia and the District of Columbia.
In April 2010, PJM and 12 member transmission owners received a U.S. Department of Energy federal stimulus grant for a project that will see PMUs installed in more than 70 substations in 10 states, as well as 17 corporate phasor data concentrators, covering about 60 percent of PJM's total transmission load. To date, 14 PMUs are installed within PJM, so this is a huge step for the company and its participating member transmission owners.
"The whole penetration of phase-angle measurement units helps us better understand the status of the whole system," said Andrew Ott, senior vice president of markets for PJM. The organization has, he explained, five operators to schedule and dispatch a thousand generators. Therefore, visualization tools are extremely important.
Broad system perspective is imperative
"The most effective visualization tools are the ones that give us a broad system perspective," Ott said. "Operators can use interactive displays to selectively migrate down to different levels." Another characteristic he says is extremely useful to operators within the interactive dashboards is the ability for each operator to customize their own display, so that the information they need to monitor is best displayed for their own particular needs. "You can save all of that as a parameter," Ott said.
"Customization seems to have been a dramatic boon for us-operators are able to determine how they best like and adapt to visualizing their own data," he added.
But it's not all plug-and-play for the RTO: PJM has also purchased visualization tools for specific projects, and then customized and adapted them to fit the needs of the project itself.
SDG&E adds anemometers
On the other side of the country, San Diego Gas & Electric (SDG&E) is finding visualization tools extremely important to its operations, too. A subsidiary of Sempra Energy, SDG&E is a regulated public utility that provides electricity and natural gas to 3.4 million consumers in San Diego and southern Orange counties, with a coverage area spanning 4,100 square miles.
Wind and weather (in particular, Santa Ana winds) are pivotal information points for this utility, and mapping, situational awareness, SCADA switches and even their own weather anemometers have proved imperative for operational awareness. "In 2003 and 2007 there were some devastating fires (in California). Some were attributed
to power lines. So we now have a full-time meteorologist on staff, and we've gone out in remote areas where even the National Weather Service did not have information to get specific weather information," said Daniel Zaragoza, SDG&E's director of electric distribution operations.
"The (National Weather Service) would run a model and take estimated information based on weather they're getting from weather stations that are miles and miles apart. We've brought in and installed anemometers in pockets in the most wind-prone areas adjacent to or right on our circuit, to be able to tell specifically or within a certain area what the winds and the weather are doing," he said.
Right now, SDG&E has a total of 93 anemometers/wind meters installed on its lines. "It's the fourth-largest weather-monitoring infrastructure in the nation. We believe we have the densest network of weather stations of anywhere in the United States," Zaragoza said of the system. "We have instruments where data was never collected before."
Real-time weather tools
And the data, which is being collected by SDG&E and verified every 10 minutes by a weather information service based in Houston, is being used for real-time operations. "For example, last year we had a circuit that tripped, and it was during a storm that hit us during the time when fire danger was still high," Zaragoza said. "Well, in those cases, we don't like to test our circuits, we want to patrol them to make sure we find any problems. But in looking at the relative humidity, and looking at what the temperature was, our meteorologist knew that it was raining-so basically the fire danger was nonexistent. We closed the circuit. It held. And the problem was attributed to lightning."
SDG&E also subscribes to real-time lightning data. "Within our 500 kV line that is an interconnection between San Diego and out to the east in Arizona, we have two segments that are just over 80 miles long. Two years ago, we had a lightning storm come through, and the line tripped. We were able to go in, because we get real-time lightning data, and pinpoint exactly where it was-it gives us a GPS coordinate. We gave that to the pilot, he zeroed in, and he found the problem within two structures," Zaragoza said.
The real-time lightning data is overlaid on a Google map, and will pinpoint lightning strikes on the line. As well, if lightning strikes away from the line, a ruler tool can measure the distance from the strike to the line, to better determine potential problems. "What it does is expedite the patrol. We can get the line in a lot quicker, and that increases the reliability of our system," he said. "That is a major interconnection for us, and we only have two right now. So one being out puts us at risk with the remaining interconnection."
Weather awareness tools aren't the only data visualization tools SDG&E uses in its operations, either. As Caroline Winn, the company's vice president of customer service, said: "We're trying to get the most amount of intelligence on our grid to help our operators to have that 24/7 situational awareness of what is going on in the system."