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On the phone, we dissected SCADA for all its worth, picking apart substation from data collection, operations from corporate, old from new. Mark Browning, technical specialist of real-time systems with the information services department of ComEd, explained that the major difference between the present and the future of supervisory control and data acquisition (SCADA) systems isn’t really a rebirth, but an addition-and it’s really in the details.
“The old system was all about data,” he told me. “But the future is about knowledge.”
Data and knowledge do, indeed, seem to represent the sliding scale of evolving SCADA philosophy. What began as rather limited collection of information from connected substations-whether switches are open or closed for example-has become a way to stay ahead of the game for utilities verging on a competition market. And since the Web reigns in this new electric world, SCADA is going Internet.
Bringing in Web-based technology has opened the data floodgates, and while the major change for ComEd (and other utilities updating their SCADA) may initially appear to be the openness-the ability to now access SCADA from a PC-Browning traces the real center of the SCADA revolution back to the substation fringes.
“SCADA is many things to many people, especially in a large utility, but it starts with field equipment in a substation,” Browning stated.
Indeed, SCADA, at its basic level, begins with microprocessor-based relays and RTUs (remote terminal units)-both now referred to as IEDs, or intelligent electronic devices. The IEDs are plugged into CTs and PTs (current transformers and potential transformers) to bring back measurements from the substation; those IEDs are also wired to contacts for “status points,” as Browning refers to them.
Once past the substation, SCADA begins to scatter in pigeonholed directions.
“To the field people, SCADA means the instrumentation in the substation; to the operations people, SCADA is the system that they use to monitor and control,” he pointed out.
Updated Web-based SCADA opens that data to even more employees, expanding beyond field and operations-with the exception of the marketing department, which is prohibited to see such information by FERC-and reaching as high as the corporate executive. And more advanced equipment at the substation level is making even more detailed information available for dissemination.
Data from the field
Browning sees the computerization of the substation as the basis for the SCADA evolution. The traditional system centered on an RTU and electromechanical relays responsible for equipment protection. These days, those two devices have merged in the microprocessor-based relay, a computer that does both tasks. As more of these “micro-computers” are attached to devices in the substations, the sheer volume of available data skyrockets.
“We had an example here [at ComEd],” Browning commented. “A substation with a traditional SCADA RTU was bringing back approximately 750 data points from that substation. We went through and we updated all the equipment to modern IEDs and that data count increased-easily-by an order of ten.”
With so much information available, interests in the data begin to diverge-leading to the need to bring this information to the individual. Traditionally, each employee would have to go directly to the SCADA operator and make requests for print outs or information. While the SCADA operator’s main job included control and monitoring, he would have to take time out to supply information to other departments.
“Having this data available on a corporate Intranet changes all of that,” Browning said.
Anytime, anywhere SCADA
Connecting SCADA information to a Web-based system opens up both information and time. The SCADA operator doesn’t have to take precious minutes to find information for another department, and the requestor doesn’t have to wait around for the SCADA operator to get around to tracking down the information when he can. ComEd sees this as a definite advantage.
“They [individuals making requests of the SCADA operator] can go to a Web browser and look at the status of any of our substations that we have and see immediately what’s going on in that substation,” Browning observed.
Anytime access seems to be a major advantage to Web-based SCADA at ComEd, which breaks down their own SCADA architecture to include both operations (the SCADAnet including traditional SCADA and EMS along with SCADA Historian and SCADA Web) and corporate (a three-pronged tier of “maintenance, management workstation”; “planning, historian, clients”; and “protection, analysis, applications”). (See figure.)
Evolving past mere data
The unregulated side of ComEd is developing SCADA even further, according to Browning. Software (referred to as eQuator) is in the works that finally moves SCADA from the traditional format of information to the future of SCADA: knowledge, thinking through that data to find conclusions.
“It’s [eQuator] a data mining tool that uses a multidimensional database and neural net technology,” Browning said. “It looks at the data over time and it searches for patterns, highlighting anomalies in large volumes of data.”
ComEd, it seems, is riding the cutting edge of web-based SCADA. Browning points to two major points setting ComEd ahead in the game. First, since ComEd still had in-house resources that had put together the previous SCADA system, they had a knowledge base readily available for combing. Add that to the number of “past unfortunate incidents” Chicago has had with regards to reliability-which pushed ComEd toward automation faster than most-and you have a frontrunner in SCADA emerging. With microprocessor-based relays at the substation level, a SCADAnet tied through a firewall (for security) to the corporate intranet and a software system working to make that increased data applicable, ComEd is thoroughly prepped for even further SCADA exploration.
“I was at a conference last week, and a colleague put up a picture [of SCADA architecture] saying, ‘This is our vision for the future,'” Browning commented. “After he spoke I took him aside and asked, ‘Can I get a copy of that? This is what we’re doing now.'”