Transformers¶
Definition¶
Roseau Load Flow can model single-phase, center-tapped and three-phase transformers.
Transformer parameters¶
Transformers are modeled with the following parameters:
\(\mathrm{VG}\): the vector group of the transformer. This parameter is called
vg
in the code.\(U_\mathrm{HV}\): the phase-to-phase nominal voltage of the high voltage side (in V). This parameter is called
uhv
in the code.\(U_\mathrm{LV}\): the phase-to-phase nominal voltage of the low voltage side (in V). This parameter is called
ulv
in the code.\(S^n\): the nominal power of the transformer (in VA). This parameter is called
sn
in the code.\(Z_2\): the series impedance located at the low voltage side of the transformer. It represents non-ideal transformer losses due to winding resistance and leakage reactance. This parameter is called
z2
in the code.\(Y_m\): the magnetizing admittance located at the high voltage side of the transformer. It represents non-ideal transformer losses due to core magnetizing inductance and iron losses. This parameter is called
ym
in the code.
The vector group defines the type of transformer and its high voltage and low voltage winding configuration:
"Ii0"
or"Ii6"
: a single-phase transformer, in-phase or in opposition respectively;"Iii0"
or"Iii6"
: a center-tapped transformer, in-phase or in opposition respectively;"Dd0"
,"Dyn11"
, etc.: a three-phase transformer with different winding configurations. For a full list of supported three-phase transformer configurations, please refer to the three-phase transformer models page.
\(Z_2\) and \(Y_m\) are usually obtained from the following results of open-circuit and short-circuit tests:
\(i^0\): the current during open-circuit test (in %). This parameter is called
i0
in the code.\(P^0\): the losses during open-circuit test (in W). This parameter is called
p0
in the code.\(P^\mathrm{sc}\): the losses during short-circuit test (in W). This parameter is called
psc
in the code.\(V^\mathrm{sc}\): the voltage on LV side during short-circuit test (in %). This parameter is called
vsc
in the code.
First, we define the following quantities:
\(i_\mathrm{HV}^n=\dfrac{S^n}{U_\mathrm{HV}}\): the nominal current of the high voltage winding of the transformer.
\(i_\mathrm{LV}^n=\dfrac{S^n}{U_\mathrm{LV}}\): the nominal current of the low voltage winding of the transformer.
Open-circuit and short-circuit tests¶
Open-circuit test¶
Let \(P^0\) be the no-load losses and \(i^0_\mathrm{HV}\) be the current in the high voltage winding of the transformer during the no-load (open-circuit) test. The following values can be computed:
Then, \(\underline{Y_{\mathrm{m}}}\) can be deduced:
Short-circuit test¶
Let \(P^{\mathrm{sc}}\) be the short-circuit losses and \(U_\mathrm{LV}^\mathrm{sc}\) be the voltage on LV side during the short-circuit test. The following values can be computed:
Then, \(\underline{Z_2}\) can be deduced:
Available Results¶
The following results are available for all transformers:
Result Accessor |
Default Unit |
Type |
Description |
---|---|---|---|
|
\(V\) |
2 complex arrays |
The potentials of each phase of the transformer |
|
\(A\) |
2 complex arrays |
The currents flowing into each phase of the transformer |
|
\(V\!A\) |
2 complex arrays |
The powers flowing into each phase of the transformer |
|
\(V\) |
2 complex arrays |
The phase-to-neutral voltages if the transformer has a neutral, the phase-to-phase voltages otherwise |
|
\(V\!A\) |
complex |
The total power loss in the transformer |
|
\(\mathrm{pu}\) |
number |
The loading of the transformer compared to its nominal power |
|
- |
boolean |
Indicates if the transformer loading exceeds its maximal loading |
The results with two arrays are for the first and second ends of the transformer, respectively. The
sense of currents and powers is from the corresponding bus into the transformer.
For convenience, these results are also available with the suffix _hv
and _lv
to access the
results of the high voltage and low voltage sides of the transformer, respectively. For example,
res_potentials_hv
returns a complex array of potentials of the HV side of the transformer.
Usage¶
To define the parameters of the transformers, use the TransformerParameters
class. Depending on
the information you have, you can choose between the following methods:
Using pre-defined transformers in the catalogue¶
If you don’t have all the information needed to model the transformer but you know its nominal power
and voltage, check if your transformer is already defined in the catalogue. You can then create the
transformer parameters using the from_catalogue()
method:
transformer_params = rlf.TransformerParameters.from_catalogue(
name="SE Minera A0Ak 50kVA 15/20kV(15) 410V Yzn11"
)
Refer to the catalogues page for more information.
Using open-circuit and short-circuit test results¶
If your transformer is not in the catalogue but you have the results of the open-circuit and
short-circuit tests, you can create the transformer parameters using the
from_open_and_short_circuit_tests()
method:
import roseau.load_flow as rlf
# The transformer parameters for a single-phase transformer
transformer_params_1ph = rlf.TransformerParameters.from_open_and_short_circuit_tests(
id="transformer_params_1ph",
vg="Ii0", # <--- single-phase transformer
uhv=rlf.Q_(20, "kV"),
ulv=rlf.Q_(400, "V"),
sn=rlf.Q_(160, "kVA"),
p0=rlf.Q_(300, "W"),
i0=rlf.Q_(1.4, "%"),
psc=rlf.Q_(2000, "W"),
vsc=rlf.Q_(4, "%"),
)
assert transformer_params_1ph.type == "single-phase"
# The transformer parameters for a three-phase transformer
transformer_params_3ph = rlf.TransformerParameters.from_open_and_short_circuit_tests(
id="transformer_params_3ph",
vg="Dyn11", # <--- three-phase transformer with (Δ) HV leading (Y) LV by 30°
uhv=rlf.Q_(20, "kV"),
ulv=rlf.Q_(400, "V"),
sn=rlf.Q_(160, "kVA"),
p0=rlf.Q_(300, "W"),
i0=rlf.Q_(1.4, "%"),
psc=rlf.Q_(2000, "W"),
vsc=rlf.Q_(4, "%"),
)
assert transformer_params_3ph.type == "three-phase"
# The transformer parameters for a center-tapped transformer
transformer_params_ct = rlf.TransformerParameters.from_open_and_short_circuit_tests(
id="transformer_params_ct",
vg="Iii0", # <--- center-tapped transformer
uhv=rlf.Q_(20, "kV"),
ulv=rlf.Q_(400, "V"),
sn=rlf.Q_(160, "kVA"),
p0=rlf.Q_(300, "W"),
i0=rlf.Q_(1.4, "%"),
psc=rlf.Q_(2000, "W"),
vsc=rlf.Q_(4, "%"),
)
assert transformer_params_ct.type == "center-tapped"
# Available vector groups:
print(rlf.TransformerParameters.allowed_vector_groups)
# "Dd0", "Dd6", ..., "Ii0", "Ii6", "Iii0", "Iii6",
Using the transformer parameters directly¶
If you know the \(Z_2\) and \(Y_m\) values, you can create the transformer parameters directly:
transformer_params_1ph = rlf.TransformerParameters(
id="transformer_params_1ph",
vg="Ii0",
uhv=rlf.Q_(20, "kV"),
ulv=rlf.Q_(400, "V"),
sn=rlf.Q_(160, "kVA"),
z2=rlf.Q_(0.0125 + 0.038j, "ohm"),
ym=rlf.Q_(7.5e-7 - 5.5e-6j, "S"),
)
Using data from another software¶
If you have the transformer parameters in another software, you can use the available data exchange methods to create the transformer parameters. We currently support PowerFactory and OpenDSS.
For OpenDSS, use the
from_open_dss()
method. Refer to the OpenDss section in the data exchange page for more information.For PowerFactory, use the
from_power_factory()
method. Refer to the PowerFactory section in the data exchange page for more information.
Available models¶
The following transformer models are available in Roseau Load Flow:
API Reference¶
- class TransformerParameters(id: Id, *, vg: str, uhv: float | Q_[float], ulv: float | Q_[float], sn: float | Q_[float], z2: complex | Q_[complex], ym: complex | Q_[complex], manufacturer: str | None = None, range: str | None = None, efficiency: str | None = None)
Bases:
roseau.load_flow.utils.Identifiable
,roseau.load_flow.utils.JsonMixin
,roseau.load_flow.utils.CatalogueMixin[pandas.DataFrame]
Parameters that define electrical models of transformers.
TransformerParameters constructor.
- Parameters:
id – A unique ID of the transformer parameters, typically its canonical name.
vg –
The vector group of the transformer.
For three-phase transformers,
Dyn11
denotes a delta-wye connection with -30° phase displacement. Allowed windings areD
for delta,Y
for wye,Z
for zigzag.For single-phase transformers,
Ii0
denotes a normal in-phase connection andIi6
denotes an inverted connection.For center-tapped transformers,
Iii0
denotes a normal in-phase connection andIii6
denotes an inverted connection.uhv – Rated phase-to-phase voltage of the HV side (V)
ulv – Rated no-load phase-to-phase voltage of the LV side (V)
sn – The nominal power of the transformer (VA)
z2 – The series impedance located at the LV side of the transformer.
ym – The magnetizing admittance located at the HV side of the transformer.
manufacturer – The name of the manufacturer for the transformer. Informative only, it has no impact on the load flow. It is filled automatically when the parameters when imported from the catalogue.
range – The product range for the transformer as defined by the manufacturer. Informative only, it has no impact on the load flow. It is filled automatically when the parameters when imported from the catalogue.
efficiency – The efficiency class of the transformer. Informative only, it has no impact on the load flow. It is filled automatically when the parameters when imported from the catalogue. The efficiency class used in the catalogue follows the Eco-Design requirements as defined by the EN 50629 standard.
- allowed_vector_groups: Final
Allowed vector groups for transformers.
- property type: Literal['three-phase', 'single-phase', 'center-tapped']
The type of transformer parameters.
It can be
three-phase
,single-phase
orcenter-tapped
.
- property vg: str
The vector group of the transformer.
For three-phase transformers,
Dyn11
denotes a delta-wye connection with 30° lead phase displacement. Allowed windings areD
for delta,Y
for wye,Z
for zigzag.For single-phase transformers,
Ii0
denotes a normal in-phase connection andIi6
denotes an inverted connection.For center-tapped transformers,
Iii0
denotes a normal in-phase connection andIii6
denotes an inverted connection.
- property whv: str
The HV winding of the transformer.
The following values are used: -
D
: a Delta connection -Y
orYn
: a Wye connection -Z
orZn
: a Zigzag connection -I
: single-phase
- property wlv: str
The LV winding of the transformer.
The following values are used: -
d
: a Delta connection -y
oryn
: a Wye connection -z
orzn
: a Zigzag connection -i
: single-phase -ii
split-phase (i.e center-tapped)
- property clock: int
The clock number (phase displacement) as indicated by the vector group.
- winding1
- winding2
- phase_displacement
- property orientation: float
1 for direct windings or -1 for reverse windings.
- Type:
The orientation of the transformer
- property manufacturer: str | None
The name of the manufacturer for the transformer.
Informative only, it has no impact on the load flow. It is filled automatically when the parameters are imported from the catalogue.
- property range: str | None
The product range for the transformer as defined by the manufacturer.
Informative only, it has no impact on the load flow. It is filled automatically when the parameters are imported from the catalogue.
- property efficiency: str | None
The efficiency class of the transformer.
Informative only, it has no impact on the load flow. It is filled automatically when the parameters imported from the catalogue. The efficiency class used in the catalogue follows the Eco-Design requirements as defined by the EN 50629 standard.
- classmethod from_power_factory(id: Id, *, tech: Literal[2, 'single-phase', 3, 'three-phase'], sn: float | Q_[float], uhv: float | Q_[float], ulv: float | Q_[float], vg_hv: str, vg_lv: str, phase_shift: int, uk: float | Q_[float], pc: float | Q_[float], curmg: float | Q_[float], pfe: float | Q_[float], manufacturer: str | None = None, range: str | None = None, efficiency: str | None = None) typing_extensions.Self
Create a transformer parameters object from PowerFactory “TypTr2” data.
Note that only two-winding three-phase transformers are currently supported.
- Parameters:
id – A unique ID of the transformer parameters.
tech – PwF parameter nt2ph (Technology). The technology of the transformer; either ‘single-phase’ or 2 for single-phase transformers or ‘three-phase’ or 3 for three-phase transformers.
sn – PwF parameter strn (Rated Power). The rated power of the transformer in (MVA).
uhv – PwF parameter utrn_h (Rated Voltage HV-Side). The rated phase-to-phase voltage of the transformer on the HV side.
ulv – PwF parameter utrn_l (Rated Voltage LV-Side). The rated phase-to-phase voltage of the transformer on the LV side.
vg_hv – PwF parameter tr2cn_h (Vector Group HV-Side). The vector group of the high voltage side. It can be one of ‘D’, ‘Y’, ‘Yn’, ‘Z’, ‘Zn’.
vg_lv – PwF parameter tr2cn_l (Vector Group LV-Side). The vector group of the low voltage side. It can be one of ‘d’, ‘y’, ‘yn’, ‘z’, ‘zn’.
phase_shift – PwF parameter nt2ag (Vector Group Phase Shift). The phase shift of the vector group in (degrees).
uk – PwF parameter uktr (Positive Sequence Impedance Short-Circuit Voltage). The positive sequence impedance i.e the voltage in (%) obtained from the short-circuit test.
pc – PwF parameter pcutr (Positive Sequence Impedance Copper Losses). The positive sequence impedance copper losses i.e the power in (kW) obtained from the short circuit test.
curmg – PwF parameter curmg (Magnetizing Impedance - No Load Current). The magnetizing current i.e. the current in (%) obtained from the no-load (open-circuit) test.
pfe – PwF parameter pfe (Magnetizing Impedance - No Load Losses). The magnetizing impedance i.e. the power losses in (kW) obtained from the no-load test.
manufacturer – The name of the manufacturer for the transformer. Informative only, it has no impact on the load flow.
range – The name of the product range for the transformer. Informative only, it has no impact on the load flow.
efficiency – The efficiency class of the transformer. Informative only, it has no impact on the load flow.
- Returns:
The corresponding transformer parameters object.
- classmethod from_open_dss(id: Id, *, conns: tuple[str, str], kvs: tuple[float, float] | FloatArrayLike1D, kvas: float | Q_[float] | tuple[float, float] | FloatArrayLike1D, leadlag: str, xhl: float, loadloss: float | Q_[float] | None = None, noloadloss: float | Q_[float] = 0, imag: float | Q_[float] = 0, rs: float | Q_[float] | tuple[float, float] | FloatArrayLike1D | None = None, manufacturer: str | None = None, range: str | None = None, efficiency: str | None = None) typing_extensions.Self
Create a transformer parameters object from OpenDSS “Transformer” data.
Note that only two-winding three-phase transformers are currently supported.
- Parameters:
id – The unique ID of the transformer parameters.
conns – OpenDSS parameter: Conns. Connection of the windings. One of {wye | ln} for wye connected banks or {delta | ll} for delta (line-line) connected banks.
kvs – OpenDSS parameter: KVs. Rated phase-to-phase voltage of the windings, kV. This is a sequence of two values equivalent to (Up, Us).
kvas – OpenDSS parameter: KVAs. Base kVA rating (OA rating) of the windings. Note that only one value is accepted as only two-winding transformers are accepted.
xhl – OpenDSS parameter: XHL. Percent reactance high-to-low (winding 1 to winding 2).
loadloss – OpenDSS parameter: %Loadloss. Percent Losses at rated load. Causes the %r values (cf. the %Rs parameter) to be set for windings 1 and 2.
noloadloss – OpenDSS parameter: %Noloadloss. Percent No load losses at nominal voltage. Default is 0. Causes a resistive branch to be added in parallel with the magnetizing inductance.
imag – OpenDSS parameter: %Imag. Percent magnetizing current. Default is 0. An inductance is used to represent the magnetizing current. This is embedded within the transformer model as the primitive Y matrix is being computed.
leadlag – OpenDSS parameter: LeadLag. {Lead | Lag | ANSI | Euro} Designation in mixed Delta-wye connections signifying the relationship between HV to LV winding. Default is ANSI 30 deg lag, e.g., Dy1 of Yd1 vector group. To get typical European Dy11 connection, specify either “lead” or “Euro”.
rs – OpenDSS parameter: %Rs. [OPTIONAL] Percent resistance of the windings on the rated kVA base. Only required if loadloss is not passed. Note that if rs is used along with loadloss, they have to have equivalent values. For a two-winding transformer, %rs=[0.1, 0.1] is equivalent to %loadloss=0.2.
manufacturer – The name of the manufacturer for the transformer. Informative only, it has no impact on the load flow.
range – The name of the product range for the transformer. Informative only, it has no impact on the load flow.
efficiency – The efficiency class of the transformer. Informative only, it has no impact on the load flow.
- Returns:
The corresponding transformer parameters object.
Example usage:
# DSS command: `New transformer.LVTR Buses=[sourcebus, A.1.2.3] Conns=[delta wye] KVs=[11, 0.4] KVAs=[250 250] %Rs=0.00 xhl=2.5 %loadloss=0` tp = rlf.TransformerParameters.from_open_dss( id="dss-tp", conns=("delta", "wye"), kvs=(11, 0.4), kvas=(250, 250), # alternatively pass a scalar `kvas=250` leadlag="ansi", # (Dyn1 or Yd1) or "euro" (Dyn11 or Yd11) xhl=2.5, loadloss=0, noloadloss=0, # default value used in OpenDSS imag=0, # default value used in OpenDSS rs=0, # redundant with `loadloss=0` )
- classmethod from_open_and_short_circuit_tests(id: Id, *, vg: str, uhv: float | Q_[float], ulv: float | Q_[float], sn: float | Q_[float], p0: float | Q_[float], i0: float | Q_[float], psc: float | Q_[float], vsc: float | Q_[float], manufacturer: str | None = None, range: str | None = None, efficiency: str | None = None) typing_extensions.Self
Create a TransformerParameters object using the results of open-circuit and short-circuit tests.
- Parameters:
id – A unique ID of the transformer parameters, typically its canonical name.
vg –
The vector group of the transformer.
For three-phase transformers,
Dyn11
denotes a delta-wye connection with -30° phase displacement. Allowed windings areD
for delta,Y
for wye,Z
for zigzag.For single-phase transformers,
Ii0
denotes a normal in-phase connection andIi6
denotes an inverted connection.For center-tapped transformers,
Iii0
denotes a normal in-phase connection andIii6
denotes an inverted connection.uhv – Rated phase-to-phase voltage of the HV side (V).
ulv – Rated no-load phase-to-phase voltage of the LV side (V).
sn – The nominal power of the transformer (VA).
p0 – Losses during open-circuit test (W).
i0 – Current during open-circuit test (%).
psc – Losses during short-circuit test (W).
vsc – Voltages on LV side during short-circuit test (%).
manufacturer – The name of the manufacturer for the transformer. Informative only, it has no impact on the load flow. It is filled automatically when the parameters when imported from the catalogue.
range – The product range for the transformer as defined by the manufacturer. Informative only, it has no impact on the load flow. It is filled automatically when the parameters when imported from the catalogue.
efficiency – The efficiency class of the transformer. Informative only, it has no impact on the load flow. It is filled automatically when the parameters are imported from the catalogue. The efficiency class used in the catalogue follows the Eco-Design requirements as defined by the EN 50629 standard.
- classmethod from_dict(data: JsonDict, *, include_results: bool = True) typing_extensions.Self
Create an element from a dictionary created with
to_dict()
.Note
This method does not work on all classes that define it as some of them require additional information to be constructed. It can only be safely used on the ElectricNetwork, LineParameters and TransformerParameters classes.
- Parameters:
data – The dictionary containing the element’s data.
include_results – If True (default) and the results of the load flow are included in the dictionary, the results are also loaded into the element.
- Returns:
The constructed element.
- classmethod catalogue_path() Path
Get the path to the catalogue.
- classmethod catalogue_data() DataFrame
Get the catalogue data.
- classmethod from_catalogue(name: str | Pattern[str] | None = None, *, manufacturer: str | Pattern[str] | None = None, range: str | Pattern[str] | None = None, efficiency: str | Pattern[str] | None = None, vg: str | Pattern[str] | None = None, sn: float | Q_[float] | None = None, uhv: float | Q_[float] | None = None, ulv: float | Q_[float] | None = None, id: Id | None = None) typing_extensions.Self
Build a transformer parameters from one in the catalogue.
- Parameters:
name – The name of the transformer to get from the catalogue. It can be a regular expression. The name is subject to change when the catalogue is updated. Prefer using the other filters.
manufacturer – The name of the manufacturer to get. It can be a regular expression.
range – The name of the product range to get. It can be a regular expression.
efficiency – The efficiency of the transformer get. It can be a regular expression.
vg – The vector group of the transformer to get. It can be a regular expression.
sn – The nominal power of the transformer to get.
uhv – The rated phase-to-phase voltage of the HV side of the transformer to get.
ulv – The rated no-load phase-to-phase voltage of the LV side of the transformer to get.
id – A unique ID for the created transformer parameters object (optional). If
None
(default), the id of the created object will be its name in the catalogue. Note that this parameter is not used in the data filtering.
- Returns:
The selected transformer. If several or no transformers fitting the filters are found in the catalogue, an error is raised.
- classmethod get_catalogue(name: str | Pattern[str] | None = None, *, manufacturer: str | Pattern[str] | None = None, range: str | Pattern[str] | None = None, efficiency: str | Pattern[str] | None = None, vg: str | Pattern[str] | None = None, sn: float | Q_[float] | None = None, uhv: float | Q_[float] | None = None, ulv: float | Q_[float] | None = None) DataFrame
Get the catalogue of available transformers.
You can use the parameters below to filter the catalogue. If you do not specify any parameter, all the catalogue will be returned.
- Parameters:
name – An optional name to filter the output. It can be a regular expression.
manufacturer – An optional manufacturer to filter the output. It can be a regular expression.
range – An optional product range to filter the output. It can be a regular expression.
efficiency – An optional efficiency to filter the output. It can be a regular expression.
vg – An optional vector group of the transformer. It can be a regular expression.
sn – An optional nominal power of the transformer to filter the output.
uhv – An optional rated high voltage to filter the output.
ulv – An optional rated no-load low voltage to filter the output.
- Returns:
The catalogue data as a dataframe.
- classmethod extract_windings(vg: str) tuple[str, str, int]
Extract the windings and phase displacement from a given vector group
- Parameters:
vg –
The vector group of the transformer.
For three-phase transformers,
Dyn11
denotes a delta-wye connection with -30° phase displacement. Allowed windings areD
for delta,Y
for wye,Z
for zigzag.For single-phase transformers,
Ii0
denotes a normal in-phase connection andIi6
denotes an inverted connection.For center-tapped transformers,
Iii0
denotes a normal in-phase connection andIii6
denotes an inverted connection.- Returns:
The HV winding, the LV winding, and the phase displacement.
- class Transformer(id: Id, bus_hv: roseau.load_flow.models.buses.Bus, bus_lv: roseau.load_flow.models.buses.Bus, *, parameters: roseau.load_flow.models.transformers.parameters.TransformerParameters, tap: float = 1.0, phases_hv: str | None = None, phases_lv: str | None = None, connect_neutral_hv: bool | None = None, connect_neutral_lv: bool | None = None, max_loading: float | Q_[float] = 1, geometry: shapely.geometry.base.BaseGeometry | None = None)
Bases:
roseau.load_flow.models.branches.AbstractBranch[roseau.load_flow_engine.cy_engine.CyTransformer]
A generic transformer model.
The model parameters are defined using the
parameters
argument.Transformer constructor.
- Parameters:
id – A unique ID of the transformer in the network transformers.
bus_hv – Bus to connect the HV side of the transformer.
bus_lv – Bus to connect the LV side of the transformer.
tap – The tap of the transformer, for example 1.02.
parameters – Parameters defining the electrical model of the transformer. This is an instance of the
TransformerParameters
class and can be used by multiple transformers.phases_hv – The phases of the HV side of the transformer. A string like
"abc"
or"abcn"
etc. The order of the phases is important. For a full list of supported phases, see the class attributeallowed_phases
. All phases must be present in the connected bus. By default, determined from the transformer type.phases_lv – The phases of the LV side of the transformer. Similar to
phases_hv
.connect_neutral_hv – Specifies whether the element’s neutral on the HV side should be connected to the HV bus’s neutral or left floating. By default, the elements’s neutral is connected when the bus has a neutral. If the bus does not have a neutral, the element’s neutral is left floating by default. To override the default behavior, pass an explicit
True
orFalse
.connect_neutral_lv – Similar to
connect_neutral_hv
but for the LV side.max_loading – The maximum loading of the transformer (unitless). It is used with the sn of the
TransformerParameters
to compute themax_power()
,res_loading()
andres_violated()
of the transformer.geometry – The geometry of the transformer.
- element_type: Final = 'transformer'
- allowed_phases: Final
The allowed phases for a transformer are:
P-P-P or P-P-P-N:
"abc"
,"abcn"
(three-phase transformer)P-P or P-N:
"ab"
,"bc"
,"ca"
,"an"
,"bn"
,"cn"
(single-phase transformer or HV side of center-tapped transformer)P-P-N:
"abn"
,"bcn"
,"can"
(LV side of center-tapped transformer)
- property tap: float
The tap of the transformer, for example 1.02.
- property bus_hv: roseau.load_flow.models.buses.Bus
The bus on the high voltage side of the transformer.
- property bus_lv: roseau.load_flow.models.buses.Bus
The bus on the low voltage side of the transformer.
- property phases_hv: str
The phases of the high voltage side of the transformer.
- property phases_lv: str
The phases of the low voltage side of the transformer.
- property has_floating_neutral_hv: bool
Does this transformer have a floating neutral on the HV side?
- property has_floating_neutral_lv: bool
Does this transformer have a floating neutral on the LV side?
- property parameters: roseau.load_flow.models.transformers.parameters.TransformerParameters
The parameters of the transformer.
- property res_violated: bool
Whether the transformer power loading exceeds its maximal loading.
- property res_voltages_hv: Q_[ComplexArray]
The load flow result of the transformer voltages on the HV side (V).
- property res_voltages_lv: Q_[ComplexArray]
The load flow result of the transformer voltages on the LV side (V).