Power mask

This example demonstrates how to derate or boost turbines by using a turbine model called PowerMask. We need the following imports:

%matplotlib inline
import numpy as np
import pandas as pd
import matplotlib.pyplot as plt

import foxes
import foxes.variables as FV
import foxes.constants as FC
/home/runner/work/foxes/foxes/foxes/core/engine.py:6: TqdmExperimentalWarning: Using `tqdm.autonotebook.tqdm` in notebook mode. Use `tqdm.tqdm` instead to force console mode (e.g. in jupyter console)
  from tqdm.autonotebook import tqdm

We start by creating a simple states table, this time via a pandas.DataFrame object:

sdata = pd.DataFrame(index=range(8))
sdata.index.name = FC.STATE
sdata[FV.WS] = [5.0, 8.0, 11.0, 14.0, 18.0, 20.0, 22.0, 25.0]
print(sdata)

states = foxes.input.states.StatesTable(
    data_source=sdata,
    output_vars=[FV.WS, FV.WD, FV.TI, FV.RHO],
    fixed_vars={FV.WD: 270.0, FV.TI: 0.05, FV.RHO: 1.225},
)
         WS
state      
0       5.0
1       8.0
2      11.0
3      14.0
4      18.0
5      20.0
6      22.0
7      25.0

Next, we create the power mask for these states. The idea is that for each state and turbine, we can set a maximal power value in a table.

  • If the calculated power value is above this value, the turbine is derated.

  • If the maximal power exceeds the nominal power of the turbine type and the calculated value is at nominal power, then the turbine is boosted to the maximal power value.

  • If the maximal power value in the power mask is NaN, then the turbine is neither derated nor boosted (normal operation)

Again we create a DataFrame that contains the power mask data:

pmask = pd.DataFrame(index=sdata.index, columns=[f"PMax_{i}" for i in range(5)])
pmask.loc[np.s_[:4], "PMax_4"] = 1000
pmask.loc[np.s_[4:], "PMax_4"] = 6000
pmask.loc[np.s_[2:], "PMax_2"] = 3000
pmask.loc[0, "PMax_0"] = 300.0
pmask.loc[3, "PMax_0"] = 1000.0
print(pmask)
       PMax_0 PMax_1 PMax_2 PMax_3 PMax_4
state                                    
0       300.0    NaN    NaN    NaN   1000
1         NaN    NaN    NaN    NaN   1000
2         NaN    NaN   3000    NaN   1000
3      1000.0    NaN   3000    NaN   1000
4         NaN    NaN   3000    NaN   6000
5         NaN    NaN   3000    NaN   6000
6         NaN    NaN   3000    NaN   6000
7         NaN    NaN   3000    NaN   6000

Using this data we can now create the model book. Notice how the variable FV.MAX_P is set to the above values via the turbine model SetFarmVars:

mbook = foxes.models.ModelBook()
mbook.turbine_models["set_Pmax"] = foxes.models.turbine_models.SetFarmVars()
mbook.turbine_models["set_Pmax"].add_var(FV.MAX_P, pmask)

We can now create a wind farm that consists of 5 turbines in a row. Some thoughts about the turbine_models argument:

  • The actual PowerMask turbine model is pre-defined in the default ModelBook under the name PMask, so we can just add it to the turbine model list.

  • It should appear after the turbine type model NREL5, since PMask corrects the results od the latter.

  • Furthermore, PMask should be placed somewhere after the above created turbine model set_Pmax in the list of turbine models, such that the values of the variable FV.MAX_P are present at the time when PMask is called.

  • The models NREL5 and set_Pmax have no influence on each other, so their order does not matter.

We choose the following pattern:

models = ["NREL5MW", "set_Pmax", "PMask"]

farm = foxes.WindFarm()
foxes.input.farm_layout.add_row(
    farm,
    xy_base=[0.0, 0.0],
    xy_step=[600.0, 0.0],
    n_turbines=5,
    turbine_models=models,
)
Turbine 0, T0: xy=(0.00, 0.00), NREL5MW, set_Pmax, PMask
Turbine 1, T1: xy=(600.00, 0.00), NREL5MW, set_Pmax, PMask
Turbine 2, T2: xy=(1200.00, 0.00), NREL5MW, set_Pmax, PMask
Turbine 3, T3: xy=(1800.00, 0.00), NREL5MW, set_Pmax, PMask
Turbine 4, T4: xy=(2400.00, 0.00), NREL5MW, set_Pmax, PMask

We can now setup our algorithm and run the calculation:

algo = foxes.algorithms.Downwind(
    farm,
    states,
    rotor_model="centre",
    wake_models=["Bastankhah2014_linear_k002"],
    mbook=mbook,
    verbosity=0,
)
# run calculation with power mask:
farm_results = algo.calc_farm()

fr = farm_results.to_dataframe()
print(fr[[FV.WD, FV.AMB_REWS, FV.REWS, FV.MAX_P, FV.AMB_P, FV.P]])

o = foxes.output.FarmResultsEval(farm_results, algo=algo)
P0 = o.calc_mean_farm_power(ambient=True)
P = o.calc_mean_farm_power()
print(f"\nFarm power: {P / 1000:.1f} MW, Efficiency = {P / P0 * 100:.2f} %")

# this output is needed later:
o1 = foxes.output.StateTurbineMap(farm_results)
DefaultEngine: Selecting engine 'single'
SingleChunkEngine: Calculating 8 states for 5 turbines
SingleChunkEngine: Starting calculation using a single worker.
SingleChunkEngine: Completed all 1 chunks

                  WD  AMB_REWS       REWS    MAXP   AMB_P            P
state turbine                                                         
0     0        270.0       5.0   5.000000   300.0   300.0   300.000000
      1        270.0       5.0   3.814333     NaN   403.9   152.226447
      2        270.0       5.0   3.004044     NaN   403.9    41.054862
      3        270.0       5.0   2.700983     NaN   403.9     0.000000
      4        270.0       5.0   3.393295  1000.0   403.9    94.460109
1     0        270.0       8.0   8.000000     NaN  1771.1  1771.100000
      1        270.0       8.0   5.128065     NaN  1771.1   446.635323
      2        270.0       8.0   4.359059     NaN  1771.1   258.919060
      3        270.0       8.0   4.099654     NaN  1771.1   200.241668
      4        270.0       8.0   3.951652  1000.0  1000.0   171.066712
2     0        270.0      11.0  11.000000     NaN  4562.5  4562.500000
      1        270.0      11.0   7.076801     NaN  4562.5  1232.043950
      2        270.0      11.0   6.019159  3000.0  3000.0   746.213686
      3        270.0      11.0   5.535896     NaN  4562.5   582.728497
      4        270.0      11.0   5.273279  1000.0  1000.0   495.093119
3     0        270.0      14.0  14.000000  1000.0  1000.0  1000.000000
      1        270.0      14.0  13.700019     NaN  5000.0  5000.000000
      2        270.0      14.0  11.839649  3000.0  3000.0  3000.000000
      3        270.0      14.0  10.930555     NaN  5000.0  4485.131576
      4        270.0      14.0   7.961268  1000.0  1000.0  1000.000000
4     0        270.0      18.0  18.000000     NaN  5000.0  5000.000000
      1        270.0      18.0  17.187485     NaN  5000.0  5000.000000
      2        270.0      18.0  16.463170  3000.0  3000.0  3000.000000
      3        270.0      18.0  16.261242     NaN  5000.0  5000.000000
      4        270.0      18.0  15.581024  6000.0  6000.0  6000.000000
5     0        270.0      20.0  20.000000     NaN  5000.0  5000.000000
      1        270.0      20.0  19.377532     NaN  5000.0  5000.000000
      2        270.0      20.0  18.860311  3000.0  3000.0  3000.000000
      3        270.0      20.0  18.740360     NaN  5000.0  5000.000000
      4        270.0      20.0  18.324416  6000.0  6000.0  6000.000000
6     0        270.0      22.0  22.000000     NaN  5000.0  5000.000000
      1        270.0      22.0  21.479271     NaN  5000.0  5000.000000
      2        270.0      22.0  21.069617  3000.0  3000.0  3000.000000
      3        270.0      22.0  20.983044     NaN  5000.0  5000.000000
      4        270.0      22.0  20.671459  6000.0  6000.0  6000.000000
7     0        270.0      25.0  25.000000     NaN  5000.0  5000.000000
      1        270.0      25.0  24.716553     NaN  5000.0  5000.000000
      2        270.0      25.0  24.480492  3000.0  3000.0  3000.000000
      3        270.0      25.0  24.419949     NaN  5000.0  5000.000000
      4        270.0      25.0  24.230227  6000.0  6000.0  6000.000000

Farm power: 15.2 MW, Efficiency = 87.64 %

For a visualization of the results, let’s re-run the case without the power mask:

# reset, for run calculation without power mask:
for t in farm.turbines:
    t.models.remove("set_Pmax")
    t.models.remove("PMask")
farm_results = algo.calc_farm()
o0 = foxes.output.StateTurbineMap(farm_results)
DefaultEngine: Selecting engine 'single'
SingleChunkEngine: Calculating 8 states for 5 turbines
SingleChunkEngine: Starting calculation using a single worker.
SingleChunkEngine: Completed all 1 chunks

We are now in the position to create plots that compare the turbine power results, using the two output objects o0 and o1:

# show power:
fig, axs = plt.subplots(1, 3, figsize=(15, 5))
o0.plot_map(
    FV.P,
    ax=axs[0],
    edgecolor="white",
    title="Power, no power mask",
    cmap="YlOrRd",
    vmin=0,
    vmax=np.nanmax(pmask),
)
o1.plot_map(
    FV.MAX_P,
    ax=axs[1],
    edgecolor="white",
    cmap="YlOrRd",
    title="Power mask",
    vmin=0,
    vmax=np.nanmax(pmask),
)
o1.plot_map(
    FV.P,
    ax=axs[2],
    edgecolor="white",
    cmap="YlOrRd",
    title="Power, with power mask",
    vmin=0,
    vmax=np.nanmax(pmask),
)
plt.show()
../_images/0a5824a07e2372b182176584a73228dd5ca86c3de1d407f7d41d8a45c2126f18.png

Similarly, for the thrust coefficients:

# show ct:
fig, axs = plt.subplots(1, 3, figsize=(15, 5))
o0.plot_map(
    FV.CT,
    ax=axs[0],
    edgecolor="white",
    title="ct, no power mask",
    cmap="YlGn",
    vmin=0,
    vmax=1.0,
)
o1.plot_map(
    FV.MAX_P,
    ax=axs[1],
    edgecolor="white",
    cmap="YlOrRd",
    title="Power mask",
    vmin=0,
    vmax=np.nanmax(pmask),
)
o1.plot_map(
    FV.CT,
    ax=axs[2],
    edgecolor="white",
    cmap="YlGn",
    title="ct, with power mask",
    vmin=0,
    vmax=1.0,
)
plt.show()
../_images/1d7ea508d6a55020a08de5caae5fb2932eb04733b68d94d3cc6f4927d1b7d7ab.png

The above visualizations demonstrate that the power mask has effects on both the produced power and ct. Hence, also wakes are affected by derating and boosts.

We can also visualize the effect of the PowerMask model on power and thrust curve, here for the case of derating from 5 MW to 3 MW:

o = foxes.output.TurbineTypeCurves(mbook)
plot_data = o.calc_plot_data("NREL5MW", [FV.P, FV.CT], P_max=3000.0)
fig, axs = plt.subplots(1, 2, figsize=(10, 4))
o.plot_curves(plot_data, axs=axs)
plt.show()
DefaultEngine: Selecting engine 'single'
SingleChunkEngine: Calculating 301 states for 1 turbines
SingleChunkEngine: Starting calculation using a single worker.
SingleChunkEngine: Completed all 1 chunks

DefaultEngine: Selecting engine 'single'
SingleChunkEngine: Calculating 301 states for 1 turbines
SingleChunkEngine: Starting calculation using a single worker.
SingleChunkEngine: Completed all 1 chunks
../_images/c97cc4d43eb86f299b602f585c543de4aaa6f4e182a88c2398ec59e582876640.png