symmetrical_components_to_abc

typhoon.test.transformations.symmetrical_components_to_abc(signals: DataFrame, method='Fortescue')

Implements the Inverse Symmetrical Transformation to abc coordinates.

The Inverse Symmetrical transformation results in an unbalanced three-phase system (abc), resulting of "zero", "positive" and "negative" components.

Parameters:

• signals (pandas.DataFrame) –

  Complex signals with three columns:

  • First column: The Zero sequence,

  • Second column: The Positive sequence and,

  • Third column: The Negative sequence.

• method (string) – Enables the choice of the inverse transformation method. Allowed values are ‘Fortescue’ or ‘Power invariant’; other values will raise an exception. Default is method="Fortescue".

Returns:

DataFrame containing three columns - one for each output signal. The labels to select the columns are "a", "b" and "c", respectively.

Return type:

pandas.DataFrame

Examples

Using typhoon.test.transformations.symmetrical_components_to_abc() and typhoon.test.signals.pandas_3ph_sine() to inverse symmetrical components can be used:

>>> import numpy as np
>>> import pandas as pd
>>>
>>> from typhoon.test.transformations import (
>>>     abc_to_symmetrical_components,
>>>     symmetrical_components_to_abc
>>> )
>>> from typhoon.test.signals import pandas_3ph_sine
>>>
>>> amplitude = 1
>>> frequency = 50
>>> duration = 1
>>> Ts = 1e-4
>>>
>>> signals = pandas_3ph_sine(amplitude, frequency, duration)
>>>
>>> zpn_fortescue = abc_to_symmetrical_components(signals)  # method="fortescue"
>>> abc_inv_zpn_fortescue = symmetrical_components_to_abc(zpn_fortescue)  # method="fortescue"
>>>
>>> zpn_power_invar = abc_to_symmetrical_components(signals, "Power invariant")
>>> abc_inv_zpn_power_invar = symmetrical_components_to_abc(zpn_power_invar, "Power invariant")

See also

typhoon.test.transformations.abc_to_symmetrical_components