Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Implementation of a Two-Axis Servo-Hydraulic System for Full-Scale Fatigue Testing of Wind Turbine Blades

Conference ·
OSTI ID:12200
;  [1];  [2]
  1. National Renewable Energy Lab., Golden, CO (US)
  2. Stensland Technologies (US)
Recently, the blade fatigue testing capabilities at NREL were upgraded from single-axis to two-axis loading. To implement this, several practical challenges were addressed, as hardware complexity increased dramatically with two actuators applying the loads at right angles to each other. A custom bellcrank was designed and implemented to minimize the load angle errors and to prevent actuator side loading. The control system was upgraded to accept load and displacement feedback from two actuators. The inherent long strokes uniquely associated with wind turbine blade-tests required substantial real-time corrections for both the control and data systems. A custom data acquisition and control system was developed using a National Instruments LabVIEW platform that interfaces with proprietary servo-hydraulic software developed by MTS Corporation. Before testing, the program is run under quasi-static (slow speed) conditions and iterates to determine the correct operational control parameters for the controller, taking into consideration geometry, test speed, and phase angle errors between the two actuators. Comparisons are made between single-axis and two-axis test loads using actual test load data and load uncertainties are qualitatively described. To date, two fatigue tests have been completed and another is currently ongoing using NREL's two-axis capability.
Research Organization:
National Renewable Energy Lab., Golden, CO (US)
Sponsoring Organization:
US Department of Energy (US)
DOE Contract Number:
AC36-99GO10337;
OSTI ID:
12200
Report Number(s):
NREL/CP-500-26896
Resource Type:
Conference paper/presentation
Conference Information:
Windpower '99, Burlington, VT (US), 06/20/1999--06/23/1999
Country of Publication:
United States
Language:
English