Analysis of wind turbines in yaw

Technical Report · Thu Sep 01 04:00:00 EDT 1983

DOI:https://doi.org/10.2172/7074641· OSTI ID:7074641

Wilson, R. E.; Chaiyapinunt, S.

The yaw problems of a three-bladed, downwind, horizontal axis wind turbine are examined in this report. A four-degree-of-freedom system was chosen to model the turbine. Linearized equations of rotor and nacelle motion were developed using the energy method and Lagrange's equations. Quasi-steady blade element and momentum theories were used in developing the axial induction factor and aerodynamic loads. A computer code was developed to obtain the numerical values of coefficients of the equations of motion, thus allowing the cause of yaw instability to be studied. The study indicated that yaw tracking error is primarily caused by tower shadow. However, the wind turbine studied - besides being unstable in yaw under normal operating conditions - has an additional problem in that the nacelle shape contributes to additional instability. Blade coning, in the present design, is inadequate to overcome this instability. The sensitivity of the system stiffness coefficients to the selected input parameters was studied, and results indicate that the system stiffness coefficient is highly sensitive to the coning angle. Increasing the coning angle could significantly increase the stiffness coefficient and lead to improvement of system stability.

• Research Organization: Oregon State Univ., Corvallis (USA). Dept. of Mechanical Engineering
• DOE Contract Number: AC04-76DP03533
• OSTI ID: 7074641
• Report Number(s): RFP-3678; ON: DE84013620
• Country of Publication: United States
• Language: English

Related Subjects

17 WIND ENERGY
170602* -- Wind Energy Engineering-- Turbine Design & Operation
COMPUTERIZED SIMULATION
DIFFERENTIAL EQUATIONS
EQUATIONS
INSTABILITY
LAGRANGE EQUATIONS
MACHINERY
MATHEMATICAL MODELS
ORIENTATION
PARTIAL DIFFERENTIAL EQUATIONS
SIMULATION
TURBINES
TURBOMACHINERY
WIND TURBINES