Smart Instrumentation, Sensors, and Software Improve Wind Power

Smart Instrumentation, Sensors, and Software Improve Wind Power
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Engineers Edge - Researchers at Purdue University and Sandia National Laboratories have developed a method that uses sensors and computational software to constantly monitor forces exerted on wind turbine blades. This method can be used to adjust the angle of attack on the turbine blades and improve the efficiency for rapidly changing wind conditions.

"The ultimate goal is to feed information from sensors into an active control system that precisely adjusts components to optimize efficiency," said Purdue doctoral student Jonathan White, who is leading the research with Douglas Adams, a professor of mechanical engineering and director of Purdue's Center for Systems Integrity.

The system would provide real-time data that would help improve wind turbine reliability and ultimately maintainability costs. This data would be readily available in the event that an excessive wind velocity event occurred and the system could prevent catastrophic wind turbine damage.

"Wind energy is playing an increasing role in providing electrical power," Adams said. "The United States is now the largest harvester of wind energy in the world. The question is, what can be done to wind turbines to make them more efficient, more cost effective and more reliable?"

The researchers imbedded an array of uniaxial and triaxial accelerometers within the turbine airfoils during manufacturing. DC type accelerometers were utilized in order to estimate the loading and deflection from both quasi-steady-state and dynamic events. This method allows an for estimation of the rotor blade static deflection and loading and then provides the electronic data for possible optimization of the turbine blades. The turbine blades are now being tested on a research wind turbine at the U.S. Department of Agriculture's Agriculture Research Service laboratory in Bushland, Texas. Personnel from Sandia and the USDA operate the research wind turbines at the Texas site.

This application of the accelerometer sensors could be instrumental in the future of turbine blades that have "control surfaces" and simple flaps like those on an airplane's wings.

"This is a perfect example of a partnership between a national lab and an academic institution to develop innovations by leveraging the expertise of both," said Jose R. Zayas, manager of Sandia's Wind Energy Technology Department.

A wind turbine's major components include rotor blades, a gearbox and generator. The wind turbine blades are made primarily of fiberglass and balsa wood and occasionally are strengthened with carbon fiber.

"The aim is to operate the generator and the turbine in the most efficient way, but this is difficult because wind speeds fluctuate," Adams said. "You want to be able to control the pitch of the turbine blades to optimize energy transfer by reducing forces on the components in the wind turbine during excessively high winds and increase the loads during low winds. In addition to improving efficiency, this should help improve reliability. The wind turbine towers can be 200 feet tall or more, so it is very expensive to service and repair damaged components."
"We envision smart systems being a potentially huge step forward for turbines," said Sandia's Rumsey. "There is still a lot of work to be done, but we believe the payoff will be great. Our goal is to provide the electric utility industry with a reliable and efficient product. We are laying the groundwork for the wind turbine of the future."

The sensors utilized are capable of measuring acceleration occurring in various directions, and also measure two types of acceleration. One type, the dynamic acceleration, results from gusting winds, while the other, called static acceleration, results from gravity and the steady background winds. It is essential to accurately measure both forms of acceleration to estimate forces exerted on the blades. The sensor data reveal precisely how much a blade bends and twists from winds.

In 2008 the United States added 8,358 megawatts of new wind-power capacity, which equates to thousands of new turbines since the average wind turbine generates 1.5 megawatts. The new capacity increased the total U.S. installed wind power to 25,170 megawatts, surpassing Germany's capacity as the world's largest harvester of wind power.
"Our aim is to do two things - improve reliability and prevent failure - and the most direct way to enable those two capabilities is by monitoring forces exerted on the blades by winds," Adams said.
The research is funded by the U.S. Department of Energy through Sandia National Laboratories. Sandia is a multi program laboratory operated by Sandia Corp., a Lockheed Martin Co., for the U.S. Department of Energy's Nation

Image:

Purdue doctoral student Jonathan White holds a cross section of a wind turbine blade like the one used in research to improve the efficiency of turbines and prevent damage to blades from high winds. The researchers, from Purdue and Sandia National Laboratories, have developed a technique that uses sensors and computational software to constantly monitor forces exerted on wind turbine blades. Such sensors could be instrumental in future turbine blades that have control surfaces and flaps like those on an airplane's wings to change the aerodynamic characteristics of the blades for better control. (Credit: Purdue University photo/Andrew Hancock)

Related Resource: Instrumentation, Electrical, Electronics Control Sensing Devices - Engineers Edge

Modified by Administrator at Mon, May 11, 2009, 11:23:08

05/11/2009, 10:41:56
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