Submitted to: American Society of Mechanical Engineers
Publication Type: Proceedings
Publication Acceptance Date: 12/15/2000
Publication Date: 3/20/2001
Citation: Sutherland, H.J., Jones, P.L., Neal, B. 2001. The long-term inflow and structural test program. American Society of Mechanical Engineers. AIAA Paper No. 2001-0039. pp.162-172. Interpretive Summary: The most expensive component of modern wind turbines is the blades. The blades need to be strong enough not to break during hurricane force winds or during periods of turbulent winds. Wind turbine blades also need to be light. At this time, the forces that an operating wind turbine encounters is not known. Three wind turbines, located at Bushland, Texas, are helping gto determine the forces that operating wind turbines encounter. One of these wind turbines is equipped with instruments to measure the dynamic forces the turbine experiences as well as the characteristics of the wind. The goal of this research is to improve the design of modern wind turbines by increasing the strength of the blades and reducing the weight.
Technical Abstract: The Long-term Inflow and Structural Test (LIST) program is collecting long-term, continuous inflow and structural response data to characterize the extreme loads on wind turbines. A heavily instrumented Micon 65/13M turbine with SERI 8m blades is being used as the primary test turbine for this test series. This turbine, and its two sister turbines, is located in nBushland, TX, a test site that exposes the turbine to a wind regime that i representative of a Great Plains commercial site. The turbines and their inflow are being characterized with 60 measurements: 34 to characterize the inflow, 19 to characterize structural response, and 7 to characterize the time-varying state of the turbine. The primary characterization of the inflow into the LIST turbine relies upon an array of five sonic anemometers. These three-axis anemometers are placed approximately 2-diameters upstream of the turbine in a pattern designed to describe the inflow. Primary characterization of the structural response of the turbin uses several sets of strain gauges to measure bending loads on the blades and the tower and two accelerometers to measure the motion of the nacelle. Data from the various instruments are sampled at a rate of 30 Hz using a newly developed data acquisition system that features a time-synchronized continuous data stream that is telemetered from the turbine rotor. The data, taken continuously, is automatically divided into 10-minute segments and archived for analysis. An integrated software analysis package is used to retrieve, order and analyze the data. Preliminary data are presented to illustrate the operation of the turbine and the data acquisition and analysis system.