Steady Operational Loads

This calculation generates wind turbine loads for a range of wind speeds \(U\) [\(\bunit{m/s}\)]. It also includes the calculation of partial derivatives which are useful for control design, and in particular for gain scheduling.

To define the range of wind speeds the user should specify the minimum and maximum values and a wind speed interval using the WindSpeedRange input.

The steady control option selected by the user will determine how the pitch \(\phi\) [\(\bunit{rad}\)] and rotor speed \(\omega\) [\(\bunit{rad/s}\)] is determined per wind speed.

An example set of inputs for a steady operational loads calculation is provided below where the turbine will be analysed at a range of wind speeds starting at \(U=4 \bunit{m/s}\) and ending at \(U=25 \bunit{m/s}\) at intervals of \(0.5 \bunit{m/s}\).

"SteadyCalculationType": "SteadyOperationalLoads"
"SteadyCalculation": {
    "WindSpeedRange": {
    "Minimum": 4.0,
    "Maximum": 25.0,
    "Interval": 0.5
    }
}

Assumptions

The whole turbine structure is simulated. This calculation will respect the flexibility option specified by the user for the Blade and Tower. The wind speed is assumed uniform across the entire turbine.

To compute a steady state solution for a particular operating point the rotor loading is assumed azimuth independent. A range of features are disabled to make the rotor loading azimuth independent. However drive train tilt is not disabled and neither is the presweep and prebend. These will introduce azimuth dependence in the aerodynamics loading calculation.