roseau.load_flow.sym¶

Symmetrical components utilities.

Attributes¶

`PositiveSequence`	Unit vector of positive-sequence components of a three-phase system.
`NegativeSequence`	Unit vector of negative-sequence components of a three-phase system.
`ZeroSequence`	Unit vector of zero-sequence components of a three-phase system.
`A`	A matrix: transformation matrix from phasor to symmetrical components.

Functions¶

`phasor_to_sym`(→ roseau.load_flow.typing.ComplexArray)	Compute the symmetrical components (0, +, -) from the phasor components (a, b, c).
`sym_to_phasor`(→ roseau.load_flow.typing.ComplexArray)	Compute the phasor components (a, b, c) from the symmetrical components (0, +, -).
`series_phasor_to_sym`(→ pandas.Series)	Compute the symmetrical components (0, +, -) from the phasor components (a, b, c) of a series.

Module Contents¶

PositiveSequence: Final[ComplexArray]¶

Unit vector of positive-sequence components of a three-phase system.

Type:: ndarray[complex]

NegativeSequence: Final[ComplexArray]¶

Unit vector of negative-sequence components of a three-phase system.

Type:: ndarray[complex]

ZeroSequence: Final[ComplexArray]¶

Unit vector of zero-sequence components of a three-phase system.

Type:: ndarray[complex]

A: Final¶

A matrix: transformation matrix from phasor to symmetrical components.

Type:: ndarray[complex]

phasor_to_sym(v_abc: ComplexArrayLike1D) → ComplexArray¶: Compute the symmetrical components (0, +, -) from the phasor components (a, b, c).

sym_to_phasor(v_012: ComplexArrayLike1D) → ComplexArray¶: Compute the phasor components (a, b, c) from the symmetrical components (0, +, -).

series_phasor_to_sym(s_abc: Series) → Series¶

Compute the symmetrical components (0, +, -) from the phasor components (a, b, c) of a series.

Parameters:: s_abc – Series of phasor components (voltage, current, …). The series must have a multi-index with a ‘phase’ level containing the phases in order (a -> b -> c).
Returns:: Series of the symmetrical components representing the input phasor series. The series has a multi-index with the phase level replaced by a ‘sequence’ level of values (‘zero’, ‘pos’, ‘neg’).

Example

Say we have a pandas series of three-phase voltages of every bus in the network:

>>> voltage
bus_id  phase
vs      an       200000000000.0+0.00000000j
        bn      -10000.000000-17320.508076j
        cn      -10000.000000+17320.508076j
bus     an       19999.00000095+0.00000000j
        bn       -9999.975000-17320.464775j
        cn       -9999.975000+17320.464775j
Name: voltage, dtype: complex128

We can get the zero, positive, and negative sequences of the voltage using:

>>> voltage_sym_components = series_phasor_to_sym(voltage)
>>> voltage_sym_components
bus_id  sequence
bus     zero        3.183231e-12-9.094947e-13j
        pos         1.999995e+04+3.283594e-12j
        neg        -1.796870e-07-2.728484e-12j
vs      zero        5.002221e-12-9.094947e-13j
        pos         2.000000e+04+3.283596e-12j
        neg        -1.796880e-07-1.818989e-12j
Name: voltage, dtype: complex128

We can now access each sequence of the symmetrical components individually:

>>> voltage_sym_components.loc[:, "zero"]  # get zero sequence values
bus_id
bus     3.183231e-12-9.094947e-13j
vs      5.002221e-12-9.094947e-13j
Name: voltage, dtype: complex128