Wind Farm Control Terminology
Wind farm control terminology is not used consistently across the research and industrial communities. This page is a reference of preferred language to develop consistent terms across the field.
Note for reference taxonomy of terms created by DTU in the FarmConners project:
Initially suggested by Adam Stock, Scott Dallas, Valentin Chabaud, Konstanze Kölle and Laurence Morgan
| Name | Description |
|---|---|
| Wake Steering | The yawing or tilting of turbines to redirect the flow of the turbine wake, typically to increase the power output of the wind farm. |
| Induction Control | Altering the induction factor of the turbine rotor to change/optimise the velocity deficit of the wake, typically to maximise wind farm power, or alter the interaction between the wake and the ambient wind to enhance wake recovery. |
| Active Wake Control | Using periodic control actuations on a turbine, such as periodic pitching, to introduce instabilities into the wake and accelerate wake recovery. |
| High Frequency Active Power investigation | Altering the active power output of the wind farm (and/or individual turbines within the farm) at a time scale of the order of sub-seconds to seconds. For example, to provide synthetic inertia, droop control, Fast Frequency Response etc. |
| Low Frequency Active Power investigation | Altering the active power output of the wind farm (and/or individual turbines within the farm) at a time scale of the order of minutes to hours. For example, during curtailment. |
| Fatigue Load Reduction | Controlling the wind farm to reduce the fatigue loads of one or more turbines within the wind farm (In combination with some other control objective). |
Ambient wind is the undisturbed wind conditions i.e., the conditions if no turbines are present
| Category | Name | Description |
|---|---|---|
| Rotor Averaged Effects | Ambient wind dynamics spatially averaged to the scale of rotors, driving global rotor dynamics and wake dynamics | |
| Wind speed | The wind speed. | |
| Direction | The direction of the wind flow. | |
| Lateral correlation (perpendicular to wind direction) | The coherence of the spatially averaged turbulence in the lateral direction. | |
| Longitudinal correlation (aligned with wind direction) | The coherence/advection of the spatially averaged turbulence in the longitudinal (along wind) direction. | |
| Transients | Gusts, lulls, wind direction changes and other large transient flow structures due to weather events. | |
| Local Rotor/Blade Effects | Ambient wind dynamics spatially averaged to a smaller scale than the rotor, driving aero- elastic dynamics. | |
| High-frequency turbulence | The wind speed. | |
| Wind shear | Variation in wind speed across the rotor. | |
| Wind veer | Directional variation across the rotor. |
Disturbed flow is the modification of the flow due to the presence of wind turbines.
| Category | Name | Description |
|---|---|---|
| Wake Effects | Wake effects are alterations to the flow down stream of individual turbines (though they may combine) | |
| Induced Turbulence | Alterations to the turbulence of the wind flow sue to the presence and operation of upstream wind turbine(s). | |
| Deflection | The persistent lateral movement of wakes (with a non-zero mean direction) | |
| Meandering | The oscillatory lateral movement of wakes (with a zero mean direction). | |
| Advection | The transport of the wake with the longitudinal wind. | |
| Profile | The spatial distribution and magnitude of the velocity deficit. | |
| Atmospheric Boundary Layer Effects | The alteration of the flow due to the wind farm as a whole and its interactions with the atmosphere. | |
| Vertical distribution (Profile) | Effects that alter the wind speed or direction in the vertical plane. | |
| Longitudinal (along wind evolution) | Evolution of the boundary layer thickness in the along wind direction. |
Simulation properties are the general properties of the simulation at a high level
| Category | Name | Description |
|---|---|---|
| Time variability | Time variability is how the wind changes over time. | |
| Steady State | Steady state processes change quasi-statically over time (the mean value is of interest). | |
| Stationary | The statistical properties of the process do not vary through the simulation (the statistical properties are of interest). | |
| Transient | The statistical properties of the process do vary through the simulation (the continuous/instantaneous/time domain values are of interest). | |
| Required Scale of Simulation | The required scale of simulation is the number of turbines that must be represented in a single simulation to give an accurate assessment of the control method. | |
| Single turbine | One wind turbine (the pre-generated wind field incorporates the effect of the presence of other wind turbines). | |
| Cluster | Part of a wind farm – typically 2-9 wind turbines. | |
| Farm | A whole wind farm – typically 10+ wind turbines. | |
| Utility-scale wind farm | missing |