FLASC data format#

Data used by FLASC adheres to the following conventions:

  • time represents the time, preferably in UTC

  • turbines are sequentially numbered, starting from 0, and numbers are always 3 digits long (e.g. the "8th" turbine is represented as 007)

  • pow_000 represents the power output of turbine 0

  • ws_000 represents the wind speed at turbine 0

  • wd_000 represents the wind direction at turbine 0

  • wd represents the wind direction chosen for example to represent the overall inflow direction

  • ws represents the wind speed chosen for example to represent the overall inflow speed

  • pow_ref represents the power output of the reference turbine (or average of reference turbines)

  • pow_test represents the power output of the test turbine (or average of test turbines)

import pandas as pd

# This dataframe adhere's to FLASC's data formatting requirements and could be used for
# FLASC analysis
df = pd.DataFrame(
    {
        "time": [0, 1, 2, 3, 4, 5],
        "pow_000": [100, 100, 100, 100, 100, 100],
        "pow_001": [100, 100, 100, 100, 100, 100],
        "ws_000": [10, 10, 10, 10, 10, 10],
        "ws_001": [10, 10, 10, 10, 10, 10],
        "wd_000": [270, 270, 270, 270, 270, 270],
        "wd_001": [270, 270, 270, 270, 270, 270],
    }
)

FlascDataFrame#

FLASC has historically used a pandas.DataFrame to store the data to be processed, as demonstrated above. Beginning in version 2.1, the FlascDataFrame class was introduced to provide additional methods and functionality to the data. FlascDataFrame is a subclass of pandas.DataFrame and can be used in place of a pandas.DataFrame. The following code cells provide an overview of the FlascDataFrame class and its methods. Support is added for converting between "FLASC" style data formatting and "user" formats, to make adhering to FLASC's data formatting conventions more straightforward.

Using FlascDataFrame#

# The above pandas.DataFrame can be converted to a FlascDataFrame directly
from flasc import FlascDataFrame

fdf = FlascDataFrame(df)
print(fdf.head())
FlascDataFrame in FLASC format
   time  pow_000  pow_001  ws_000  ws_001  wd_000  wd_001
0     0      100      100      10      10     270     270
1     1      100      100      10      10     270     270
2     2      100      100      10      10     270     270
3     3      100      100      10      10     270     270
4     4      100      100      10      10     270     270
# The FlascDataFrame includes a few helper functions added to the base pandas dataframe.
# The following returns the number of turbines found in the dataframe.
print(fdf.n_turbines)
2

Creating a FlascDataFrame from User Data#

More value from a FlascDataFrame is obtained when using it convert back and forth between user-formatted data and Flasc Data.

import numpy as np

# Suppose the we have a 3 turbine farm with turbines names 'TB01', 'TB02', 'TB03'
# For each turbine we have power, wind speed and wind direction data
# Assume that in the native data collection system,
# the signal names for each channel are given below

N = 20  # Number of data points

# Wind speeds
wind_speed_TB01 = np.random.rand(N) + 8.0
wind_speed_TB02 = np.random.rand(N) + 7.5
wind_speed_TB03 = np.random.rand(N) + 8.5

# Wind directions
wind_dir_TB01 = 10 * np.random.rand(N) + 270.0
wind_dir_TB02 = 10 * np.random.rand(N) + 270.0
wind_dir_TB03 = 10 * np.random.rand(N) + 270.0

# Power
power_TB01 = wind_speed_TB01**3
power_TB02 = wind_speed_TB02**3
power_TB03 = wind_speed_TB03**3

# Time
time = np.arange(N)
# Create a dictrionary storing this data, which could be used to instantiate a pandas.DataFrame
# or a FlascDataFrame
data_dict = {
    "time": time,
    "wind_speed_TB01": wind_speed_TB01,
    "wind_speed_TB02": wind_speed_TB02,
    "wind_speed_TB03": wind_speed_TB03,
    "wind_dir_TB01": wind_dir_TB01,
    "wind_dir_TB02": wind_dir_TB02,
    "wind_dir_TB03": wind_dir_TB03,
    "power_TB01": power_TB01,
    "power_TB02": power_TB02,
    "power_TB03": power_TB03,
}

The data is currently stored using the the channel and turbine names of the user. By supplying additional metadata to the FlascDataFrame, the data can be converted to and from the FLASC format.

# Declare a channel_name_map dictionary to map the signal names to the turbine names.
# The turbine numbers when 0-indexed in FLASC format should
# align with their numbering in the FLORIS model of the same farm.
channel_name_map = {
    "time": "time",
    "wind_speed_TB01": "ws_000",
    "wind_speed_TB02": "ws_001",
    "wind_speed_TB03": "ws_002",
    "wind_dir_TB01": "wd_000",
    "wind_dir_TB02": "wd_001",
    "wind_dir_TB03": "wd_002",
    "power_TB01": "pow_000",
    "power_TB02": "pow_001",
    "power_TB03": "pow_002",
}

We are now in a position to instantiate a FlascDataFrame

fdf = FlascDataFrame(data_dict, channel_name_map=channel_name_map)
print(fdf.head())
FlascDataFrame in user (wide) format
   time  wind_speed_TB01  wind_speed_TB02  wind_speed_TB03  wind_dir_TB01  \
0     0         8.042203         8.118036         9.402114     278.192856   
1     1         8.804845         7.935793         8.505325     275.532379   
2     2         8.596563         8.391969         8.940052     271.501722   
3     3         8.666591         7.900243         9.162102     270.122142   
4     4         8.168827         7.835564         8.897655     270.034042   

   wind_dir_TB02  wind_dir_TB03  power_TB01  power_TB02  power_TB03  
0     271.945625     273.934466  520.145848  534.999030  831.144579  
1     277.949229     272.648892  682.598257  499.770901  615.279944  
2     270.710139     272.537487  635.293806  591.005689  714.529392  
3     272.996751     274.904523  650.945828  493.084490  769.104646  
4     275.384336     276.686718  545.103722  481.072802  704.411926  

Converting this to the FLASC format (and back) now simply requires calling the appropriate method. This makes it convenient to work with FLASC functions (that require the data to be in FLASC format) and user-provided functions (that may require the user's formatting) within the same workflow.

# Convert now into FLASC format (as a copy)
fdf_flasc = fdf.convert_to_flasc_format()
print(fdf_flasc.head(2))

print("\n\n")
# Convert back to user format (as a copy)
fdf_user = fdf_flasc.convert_to_user_format()
print(fdf_user.head(2))

print("\n\n")
# Conversions can also happen in place, if the inplace argument is set to True
fdf.convert_to_flasc_format(inplace=True)
print(fdf.head(2))
print("\n")
fdf.convert_to_user_format(inplace=True)
print(fdf.head(2))
FlascDataFrame in FLASC format
   time    ws_000    ws_001    ws_002      wd_000      wd_001      wd_002  \
0     0  8.042203  8.118036  9.402114  278.192856  271.945625  273.934466   
1     1  8.804845  7.935793  8.505325  275.532379  277.949229  272.648892   

      pow_000     pow_001     pow_002  
0  520.145848  534.999030  831.144579  
1  682.598257  499.770901  615.279944  



FlascDataFrame in user (wide) format
   time  wind_speed_TB01  wind_speed_TB02  wind_speed_TB03  wind_dir_TB01  \
0     0         8.042203         8.118036         9.402114     278.192856   
1     1         8.804845         7.935793         8.505325     275.532379   

   wind_dir_TB02  wind_dir_TB03  power_TB01  power_TB02  power_TB03  
0     271.945625     273.934466  520.145848  534.999030  831.144579  
1     277.949229     272.648892  682.598257  499.770901  615.279944  



FlascDataFrame in FLASC format
   time    ws_000    ws_001    ws_002      wd_000      wd_001      wd_002  \
0     0  8.042203  8.118036  9.402114  278.192856  271.945625  273.934466   
1     1  8.804845  7.935793  8.505325  275.532379  277.949229  272.648892   

      pow_000     pow_001     pow_002  
0  520.145848  534.999030  831.144579  
1  682.598257  499.770901  615.279944  


FlascDataFrame in user (wide) format
   time  wind_speed_TB01  wind_speed_TB02  wind_speed_TB03  wind_dir_TB01  \
0     0         8.042203         8.118036         9.402114     278.192856   
1     1         8.804845         7.935793         8.505325     275.532379   

   wind_dir_TB02  wind_dir_TB03  power_TB01  power_TB02  power_TB03  
0     271.945625     273.934466  520.145848  534.999030  831.144579  
1     277.949229     272.648892  682.598257  499.770901  615.279944  

Converting Wide and Long#

FlascDataFrame also provides methods to convert between wide and long formats. FLASC's native format is always "wide", that is, each channel has its own column. But FlascDataFrame can be used to convert to a user format that is "long" where each channel is a row in the dataframe.

df = pd.DataFrame(
    {
        "time": time,
        "wind_speed_TB01": wind_speed_TB01,
        "wind_speed_TB02": wind_speed_TB02,
        "wind_speed_TB03": wind_speed_TB03,
        "wind_dir_TB01": wind_dir_TB01,
        "wind_dir_TB02": wind_dir_TB02,
        "wind_dir_TB03": wind_dir_TB03,
        "power_TB01": power_TB01,
        "power_TB02": power_TB02,
        "power_TB03": power_TB03,
    }
)

# Convert to "long" format; this is taken to be the user's desired format in this example.
df = pd.melt(df, id_vars=["time"], var_name="channel", value_name="value")
print(df)
     time          channel       value
0       0  wind_speed_TB01    8.042203
1       1  wind_speed_TB01    8.804845
2       2  wind_speed_TB01    8.596563
3       3  wind_speed_TB01    8.666591
4       4  wind_speed_TB01    8.168827
..    ...              ...         ...
175    15       power_TB03  697.085427
176    16       power_TB03  644.314069
177    17       power_TB03  808.018863
178    18       power_TB03  759.622635
179    19       power_TB03  624.750653

[180 rows x 3 columns]
# This time include in the specification of the FlascDataFrame the name of the
# columns of the long data
fdf = FlascDataFrame(
    df,
    channel_name_map=channel_name_map,
    long_data_columns={"variable_column": "channel", "value_column": "value"},
)
print(fdf.head())
FlascDataFrame in user (long) format
   time          channel     value
0     0  wind_speed_TB01  8.042203
1     1  wind_speed_TB01  8.804845
2     2  wind_speed_TB01  8.596563
3     3  wind_speed_TB01  8.666591
4     4  wind_speed_TB01  8.168827

The data can still be converted to FLASC format (and back)

fdf_flasc = fdf.convert_to_flasc_format()
print(fdf_flasc.head(2))
print("\n\n")
fdf_user = fdf_flasc.convert_to_user_format()
print(fdf_user.head(2))

# As before, conversions can also happen in place, if the inplace argument is set to True
FlascDataFrame in FLASC format
   time     pow_000     pow_001     pow_002      wd_000      wd_001  \
0     0  520.145848  534.999030  831.144579  278.192856  271.945625   
1     1  682.598257  499.770901  615.279944  275.532379  277.949229   

       wd_002    ws_000    ws_001    ws_002  
0  273.934466  8.042203  8.118036  9.402114  
1  272.648892  8.804845  7.935793  8.505325  



FlascDataFrame in user (long) format
   time     channel       value
0     0  power_TB01  520.145848
1     0  power_TB02  534.999030

Exporting to wind-up format#

Another use case for FlascDataFrame is to export the data into the "wind-up" format. Wind-up is an open source tool for assessing uplift provided by RES. This conversion provides a convenient way to assess the data, in the case of uplift assessment, using the wind-up tool, which is imported by FLASC. A full demonstration of the usage of the wind-up tool in FLASC is provided within the Smarteole example set.

fdf = fdf.convert_to_flasc_format()

df_windup = fdf.export_to_windup_format()  # df_windup is a pandas DataFrame
print(df_windup.head())
                       raw_ActivePowerMean  raw_YawAngleMean  \
TimeStamp_StartFormat                                          
0                               520.145848        278.192856   
1                               682.598257        275.532379   
2                               635.293806        271.501722   
3                               650.945828        270.122142   
4                               545.103722        270.034042   

                       raw_WindSpeedMean TurbineName  PitchAngleMean  \
TimeStamp_StartFormat                                                  
0                               8.042203         000               0   
1                               8.804845         000               0   
2                               8.596563         000               0   
3                               8.666591         000               0   
4                               8.168827         000               0   

                       GenRpmMean  raw_ShutdownDuration  ActivePowerMean  \
TimeStamp_StartFormat                                                      
0                            1000                     0       520.145848   
1                            1000                     0       682.598257   
2                            1000                     0       635.293806   
3                            1000                     0       650.945828   
4                            1000                     0       545.103722   

                       WindSpeedMean  YawAngleMean  ShutdownDuration  
TimeStamp_StartFormat                                                 
0                           8.042203    278.192856                 0  
1                           8.804845    275.532379                 0  
2                           8.596563    271.501722                 0  
3                           8.666591    270.122142                 0  
4                           8.168827    270.034042                 0