Power time series
The power time series calculation can be used to quantify the impact of curtailments defined in Design > Curtailment strategies and export a power time series to file.
The power time series calculation simulates wakes and power for a time series of flow cases. The ambient conditions that define the flow case are defined at each initiating measurement site location, these are then transposed to the turbine location using the speed-ups calculated by the flow model. A flow case is defined by mean wind speed, wind speed standard deviation, wind direction and air density.
The following models can be considered
- Eddy Viscosity or Modified Park wake models
- Large Wind Farm Correction
- Curtailment rules
- Correction of turbine power curve to local air density at the individual turbine locations
The power time series can be exported as a tab separated text file by checking Export intermediate results and specifying a folder path.
Power time series modelling options
The power time series calculation uses the wake and large wind farm model settings specified in the Turbine interaction settings task and it will apply the adjusted hysteresis cut-outs if that option is selected.
Assigning time series wind climates
The wind climate inputs button is for assigning the wind speed and standard deviation or turbulence intensity for each wind climate.
| Option | Description |
|---|---|
| Turbulence intensity input method | Can either be defined by selecting a standard deviation time series, which would be combined with the wind speed time series, or a turbulence intensity. |
Tip
Only climates with initiating turbines need to actually be set.
Options not associated to wind climates
| Option | Description |
|---|---|
| Wind direction time series | You must select a direction time series to define the flow case. |
| Air density | Select either time series or fixed air density. Air density time series can be calculated with a script. |
| Temperature | An optional temperature time series (Required when assessing temperature curtailments). |
| Temperature lapse rate | A lapse rate to define temperature decline per metre. |
| Quantify curtailment efficiencies | Check to calculate a break-down of the curtailment efficiencies caused by the curtailment strategies in the workbook by simulating the time series multiple times with different curtailment types included. |
| Export intermediate results | The power time series can be exported as a tab separated text file by checking Export intermediate results and specifying a folder path. |
Intermediate outputs
| Data | File name |
|---|---|
| Time series inputs (matched) | WFAPowerTimeSeriesInputs.tsv |
| Turbine operational mode | WFAPowerTimeSeries_OperationalModes.tsv |
| Waked wind speed | WFAPowerTimeSeries_WakedWindSpeeds.tsv |
| Power output | WFAPowerTimeSeries_PowerOutput.tsv |
| Ambient wind speed | WFAPowerTimeSeries_AmbientWindSpeeds.tsv |
| Temperature at turbine (if temperature set) | WFAPowerTimeSeries_TemperatureAtTurbines.tsv |
Current limitations
Note
The power time series calculates a Full power time series, not a Net power times series: It does not yet consider the blockage efficiency, or any manually definable efficiencies defined in the Net Energy section.