By John M. Powers, online/associate editor
Recently, several threats to the nation’s power grid have been made plain. Hurricanes Rita and Katrina showed the damage that extreme storms could cause, and this summer’s heat wave has put a strain on the grid. The North American blackout of 2003 certainly gave the industry much to consider when it came to an aging infrastructure and early warnings. And in the post-9/11 world, electric transmission infrastructure must be considered as a target for terrorism. Indeed, just after 9/11 in October of 2001, President Bush reaffirmed previous administrations classifications of the nation’s energy infrastructure as critical to the country and therefore should be covered by the Critical Infrastructure Protection order.
For the past two years a team of researchers at Iowa State University lead by Dr. Arun Somani have been working toward a solution to protecting the nation’s power grid. The goal of the project is to develop a system of sensors mounted on utility poles that would monitor the transmission system.
The idea came out of conversations amongst colleagues in the Iowa State power program, says Prof. Somani, chair professor of electrical and computer engineering and co-director of the Information Infrastructure Institute at Iowa State. They wanted to find a project in which information technology could offer solutions to infrastructure challenges. The sensor project was initially rejected and then accepted upon further review.
Somani said one of the primary drivers behind undertaking the project were concerns of security and terrorism enacted against the nation’s transmission infrastructure. Such a network of sensors could guard the transmission infrastructure by being equipped with cameras, either still shot or video, for visual monitoring. But the process of recovering from and/or avoiding a power outage can also be aided by the system, said Somani.
“One of the problems in power systems is detecting a problem so the information can reach the right place at the right time. It can aid the recovery process. Similar information about terrorism can also be propagated,” said Somani.
On a day-to-day basis, the network of sensors would collect information on itself, to make sure it is functioning, and monitoring the power system, attempting to notice anything out of the ordinary. If any alarms were sent up, then the utility using the system would receive an alert. For example, the system could register high wind speeds and excess cable movement in an area. That information would be sent back to the utility and they could plan accordingly. “So you can be proactive rather than reactive,” said Somani.
If recovery is the order of the day, Somani said the sensors would be able to quickly locate the problem on the transmission grid and point field crews to the site. It would save time, Somani added, rather than wait for customer calls to call centers and dispatching crews to search out any damage to the lines.
It is in being proactive and quick identification of problems that the network of sensors sets itself apart from a traditional outage management system. Another benefit of the system once it is up and running is that it won’t be constantly sending massive amounts of data back to the utility. Instead, explained Somani, it only sends information when something is wrong. And even that information is “a condensed set of information.” In other words, it has been processed and vetted by the individual sensors themselves thanks to “tiny computing engines built into them.”
So could this system of sensors have avoided the blackout of 2003? “Avoid is a strong word. I’ll shy away from saying that,” said Somani. However, Somani said the system could have certainly given pre-warning and helped in organizing a solution to the cascading blackout depending on how the system was programmed.
If the system were to be deployed across the nation, the ultimate goal, according to Somani, would be to have sensors mounted on every pole, communicating with each other and utilities wirelessly. The wireless communication side of the system is an easy implementation, said Somani. With the prevalence of wireless networks it would be easy for the network of sensors to “hook in.”
However, a nationwide deployment is still a ways off. Somani explained that most of the inquiries he’s received have asked what sort of capability the system had simply at the substation level. Still, Somani has received interest in the project from California to Tennessee. Somani has, at the time of writing, two separate meetings in the fall with companies that want to explore a demonstration of the system and a possible test. There is also an outright offer from a Midwestern company to mount his sensors on their grid. More local to the University, the city of Ames, Iowa, has expressed interest in doing a field test at their substations.
Wherever the field test is achieved, Somani expects that the research team will have at least one under their belts by the end of the year. He also expects that there will be even more interest in the system once the tests are completed. “We’re very excited about it,” added Somani.
Somani’s team is composed of several experts in fields such as wireless communications and real time systems. “It’s a good team because we have the user side, we have the application side, we have the technology side, we have the control side, and the information side. Multiple backgrounds,” said Somani.
And he’ll need their expertise as there are still some challenges to overcome. At the moment, the sensors can communicate over a range of 500 feet. The team wants the sensors to be able to communicate over a wider range but doesn’t want to add too much power to the system.
“Increasing the range of the wireless communication is a technical challenge for us. We don’t want to go and put powerful transmitters [on the sensors] because we want to operate on a very low power budget,” explained Somani. We want to “be power-wise,” Somani added.
Another challenge is finding a way to efficiently and effectively transmit data from the sensors. “How do we do efficient data merging and still keep the flavor of the information,” said Somani.
Finally, powering the sensors has proved to be a challenge. “That’s an interesting challenge. We’re working with the power system but the power supply [for the sensors] is of a different nature,” said Somani. He added that equipping every sensor with a small solar panel so the sensor can produce its own power is proving to be the best option.
The project could also see some spin-off applications. Somani said he’s already been in contact with other departments about an application for the transportation network in which the sensors would be used to monitor road conditions and accidents. Also, making the technology cheap and power-wise could have applications across other industries.