New application: Fieldbus technology breaks into electric utility industry
Two presentations at Emerson's Global Users Exchange carried the news that instrumentation and controls communicating via fieldbus technology has finally forced its way into the electric utility industry. Known for its conservatism, the power industry has been very slow to adopt new control technology, or in this case, slow to adopt proven technology. However, at least two full-sized U.S. generating plants are now under construction using fieldbus technology at the device and instrumentation level.
Omaha Public Power District, Nebraska City Unit 2 is a 660 mW coal-fired, subcritical boiler plant with standard design elements, except that it will use FOUNDATION Fieldbus and Profibus to network its instrumentation and control functions. This will give it the capability to employ HART smart instrumentation, taking full advantage of the diagnostic information the sensors generate in addition to the specific process variable. The plant is slated to come online by May 2009.
Portland General Electric, Port Westward plant on the Columbia River is a 407 mW gas-fired combined-cycle turbine plant. It will also use a combination of FOUNDATION Fieldbus and Profibus to network its instrumentation and control functions. The project is one of the first fieldbus experiences for contractor Black & Veatch, as well. Even with reluctance to try something new, PGE was convinced of the advantages of the technology and anticipates substantial savings for the installation and total life cost going forward. Moreover, they expect that the network will require less operator time than a hard-wired approach. They also intend to use HART smart instrumentation. Commercial operation is scheduled for March, 2007.
Is this a trend? Has technology now used for many years in critical process industries finally gained a foothold in a last bastion of analog and hard-wired control? The answer is a cautious "yes," but probably only for greenfield plants. "At EPRI, I've been trying to promote fieldbus for ten years," says Cyrus Taft, chief engineer for EPRI's instrumentation and control center. "Now it's reaching critical mass and becoming commercially viable for us. Still, it doesn't make sense for a retrofit. You can't just stick it on top of what's already been done. You don't just add it to existing DCS architecture. But, if your initial design of the plant is done with fieldbus in mind, the savings are tremendous. On new construction, it's a biggie."
Control Engineering Daily News Desk
Peter Welander , process industries editor