Three-Winding Transformer (Three-Phase)
A three-phase linear non-ideal three-winding transformer with a Star and Triangle windings connection and saturation consideration.
blockType: AcausalElectricPowerSystems.Passive.Transformers.ThreePhase
|
Three-Winding Transformer (Three-Phase) Path in the library: |
|
Two-Winding Transformer (Three-Phase) Path in the library: |
Description
Block Three-Winding Transformer (Three-Phase) It is a linear non-ideal three-phase three-winding transformer that transfers electrical energy between two or more circuits by means of electromagnetic induction. The block includes the effects of linear leakage of the windings and linear magnetization of the core. The block resistance can be parameterized in relative units. The connections of the primary, first secondary and second secondary windings, the triangle-star phase angle and the types of cores are adjusted.
The configuration options for the primary and secondary windings are as follows:
-
Wye with floating neutral— a star with a floating three-phase neutral. -
Wye with neutral port— a star with a three-phase neutral. -
Wye with grounded neutral— a star with a grounded three-phase neutral. -
Delta 1 o’clock— a triangle 30 degrees behind the star. -
Delta 11 o’clock— a triangle with a 30-degree advance of the star.
For more information about the operating modes of a three-phase system connected according to the Triangle scheme, see Recommendations for delta connection of transformer windings.
Core type Options:
-
Three-phase five-limb— three-phase five-rod core. -
Three-phase three-limb— three-phase three-core core.
Although a three-core is usually cheaper, a five-core has the following advantages:
-
Lower resistance for the zero sequence current component, that is, between the line and the neutral, in the case of an unbalanced load.
-
Greater heat dissipation.
The equations
Three-core core
This block is implemented in the magnetic field using blocks Nonlinear Reluctance, Winding and Eddy Current.
-1-s.png)
It is important to determine the relationship between the parameters of the electrical region from the block mask and the parameters of the magnetic region used in the model.:
-
— the number of turns of the primary winding.
-
— the number of turns of the first secondary winding.
-
— the number of turns of the second secondary winding.
-
— shunt magnetizing inductance.
-
— zero-sequence inductance.
-
— the scattering inductance of the primary winding.
-
— the scattering inductance of the first secondary winding.
-
— the scattering inductance of the second secondary winding.
-
— shunting magnetizing resistance.
-
— magnetizing resistance between phases
.
-
— zero sequence resistance coefficient
.
-
— leakage resistance of the primary winding
.
-
— leakage resistance of the first secondary winding
.
-
— leakage resistance of the second secondary winding
.
-
— the conductivity of the eddy current loop
.
For three-winding three-phase transformers, the connection between the different windings in each phase is the same.
Five-rod core
In the case of a transformer with a five-rod core, the additional magnetic flux paths provided by the additional rods can be represented using zero-sequence magnetic resistances, which were originally developed for magnetic paths through air in a transformer with a three-rod core.
-2-s.png)
In the five-core model, the magnetic resistances from the phases to the additional windings should be equal to the magnetic resistances between the phases.:
.
The conclusion follows from this:
.
Variables
Use the parameter group Initial Targets to set the priority and initial target values for the block parameter variables before modeling. For more information, see Configuring physical blocks using target values.
Ports
Conserving
#
~1
—
terminals of the primary winding
electricity
Details
Three-phase electrical port, corresponds to phase terminals , and the primary winding.
| Program usage name |
|
#
~2
—
terminals of the first secondary winding
electricity
Details
Three-phase electrical port, corresponds to phase terminals , and the first secondary winding.
| Program usage name |
|
#
~3
—
terminals of the second secondary winding
electricity
Details
Three-phase electrical port, corresponds to phase terminals , and the second secondary winding.
| Program usage name |
|
#
n2
—
neutral
electricity
Details
The electrical port connected to the neutral of the secondary winding.
Dependencies
To use this port, set the parameter Secondary winding connection type meaning Wye with neutral port.
| Program usage name |
|
#
n1
—
neutral
electricity
Details
The electrical port connected to the neutral of the primary winding.
Dependencies
To use this port, set the parameter Primary winding connection type meaning Wye with neutral port.
| Program usage name |
|
#
n3
—
neutral
electricity
Details
An electrical port connected to the neutral conductor of the tertiary winding.
Dependencies
To use this port, set the parameter Tertiary winding connection type meaning Wye with neutral port.
| Program usage name |
|
Input
#
tap_in
—
description missing
Details
Description missing
| Data types |
Description missing |
| Complex numbers support |
Description missing |
Parameters
Main
#
Number of windings —
switching between a two- and three-winding transformer
Two | Three
Details
Switching between a two- and three-winding transformer.
-
Two— the unit simulates a two-winding transformer. -
Three— the unit simulates a three-winding transformer.
| Values |
|
| Default value |
|
| Program usage name |
|
| Evaluatable |
No |
#
Rated apparent power —
Rated full power
W | uW | mW | kW | MW | GW | V*A | HP_DIN
Details
The rated power passing through the transformer. The value must be greater than 0.
| Units |
|
| Default value |
|
| Program usage name |
|
| Evaluatable |
Yes |
#
Rated electrical frequency —
Rated electrical frequency
Hz | kHz | MHz | GHz
Details
The nominal or nominal frequency of the AC network to which the transformer is connected. The value must be greater than 0.
| Units |
|
| Default value |
|
| Program usage name |
|
| Evaluatable |
Yes |
#
Primary winding connection type —
primary winding configuration
Wye with floating neutral | Wye with neutral port | Wye with grounded neutral | Delta 1 o’clock | Delta 11 o’clock
Details
The type of primary winding.
| Values |
|
| Default value |
|
| Program usage name |
|
| Evaluatable |
No |
#
Primary rated voltage —
RMS mains voltage applied to the primary winding
V | uV | mV | kV | MV
Details
RMS linear voltage applied to the primary winding under normal operating conditions. The value must be greater than 0.
| Units |
|
| Default value |
|
| Program usage name |
|
| Evaluatable |
Yes |
#
Secondary winding connection type —
secondary winding configuration
Wye with floating neutral | Wye with neutral port | Wye with grounded neutral | Delta 1 o’clock | Delta 11 o’clock
Details
The type of secondary winding.
| Values |
|
| Default value |
|
| Program usage name |
|
| Evaluatable |
No |
#
Secondary rated voltage —
RMS mains voltage applied to the secondary winding
V | uV | mV | kV | MV
Details
RMS linear voltage applied to the secondary winding under normal operating conditions. The value must be greater than 0.
| Units |
|
| Default value |
|
| Program usage name |
|
| Evaluatable |
Yes |
#
Tertiary winding connection type —
configuration of the tertiary winding
Wye with floating neutral | Wye with neutral port | Wye with grounded neutral | Delta 1 o’clock | Delta 11 o’clock
Details
The type of tertiary winding.
| Values |
|
| Default value |
|
| Program usage name |
|
| Evaluatable |
No |
#
Tertiary rated voltage —
RMS mains voltage applied to the tertiary winding
V | uV | mV | kV | MV
Details
RMS linear voltage applied to the tertiary winding under normal operating conditions. The value must be greater than 0.
| Units |
|
| Default value |
|
| Program usage name |
|
| Evaluatable |
Yes |
#
Core type —
core type
Three-phase three-limb | Three-phase five-limb
Details
The type of core.
| Values |
|
| Default value |
|
| Program usage name |
|
| Evaluatable |
No |
Impedances
# Primary winding resistance, pu — resistance of the primary winding, O.e
Details
The resistance of the primary winding, i.e. the value must be greater than 0.
| Default value |
|
| Program usage name |
|
| Evaluatable |
Yes |
# Secondary winding resistance, pu — resistance of the secondary winding, O.e
Details
Resistance of the secondary winding. The value must be greater than 0.
| Default value |
|
| Program usage name |
|
| Evaluatable |
Yes |
# Tertiary winding resistance, pu — resistance of the tertiary winding, O.e
Details
Resistance of the tertiary winding. The value must be greater than 0.
| Default value |
|
| Program usage name |
|
| Evaluatable |
Yes |
# Leakage reactance — accounting for magnetic flux losses.
Details
Enabling the simulation of magnetic flux losses.
| Default value |
|
| Program usage name |
|
| Evaluatable |
No |
# Primary leakage reactance, pu — magnetic resistance of the primary winding, O.E.
Details
Magnetic flux losses in the primary winding, i.e. the value must be greater than 0.
Dependencies
To use this option, check the box for the option Leakage reactance.
| Default value |
|
| Program usage name |
|
| Evaluatable |
Yes |
# Secondary leakage reactance, pu — magnetic resistance of the secondary winding, O.E.
Details
Magnetic flux losses in the secondary winding, i.e. the value must be greater than 0.
Dependencies
To use this option, check the box for the option Leakage reactance.
| Default value |
|
| Program usage name |
|
| Evaluatable |
Yes |
# Tertiary leakage reactance, pu — magnetic resistance of the tertiary winding, O.E.
Details
Magnetic flux losses in the tertiary winding, i.e. the value must be greater than 0.
Dependencies
To use this option, check the box for the option Leakage reactance.
| Default value |
|
| Program usage name |
|
| Evaluatable |
Yes |
# Magnetizing resistance — consideration of magnetization resistance
Details
Enabling the simulation of the magnetization resistance in the transformer core.
| Default value |
|
| Program usage name |
|
| Evaluatable |
No |
# Shunt magnetizing resistance, pu — active resistance of the magnetization branch, O.E.
Details
The active resistance of the magnetization branch, i.e., the value must be greater than 0.
Dependencies
To use this option, check the box for the option Magnetizing resistance.
| Default value |
|
| Program usage name |
|
| Evaluatable |
Yes |
# Magnetizing reactance — accounting for magnetic effects
Details
Enabling simulation of the magnetic effects of the transformer core.
| Default value |
|
| Program usage name |
|
| Evaluatable |
No |
# Magnetic saturation — representation of magnetic saturation
Details
Select this option to use magnetic saturation.
Dependencies
To use this option, check the box for the option Magnetizing reactance.
| Default value |
|
| Program usage name |
|
| Evaluatable |
No |
# Shunt magnetizing reactance, pu — reactivity of the magnetization branch, O.E.
Details
The reactance of the magnetization branch during operation of the linear domain, i.e., the value must be greater than 0.
Dependencies
To use this option, check the box for the option Magnetizing reactance and check the box Magnetic saturation.
| Default value |
|
| Program usage name |
|
| Evaluatable |
Yes |
# Current vector, pu — vector of current values, O.E.
Details
The vector of current values, i.e. the first value should be 0, the rest are strictly ascending.
Dependencies
To use this option, check the box for the option Magnetizing reactance and check the box Magnetic saturation.
| Default value |
|
| Program usage name |
|
| Evaluatable |
Yes |
# Magnetic flux vector, pu — vector of flow values, O.e
Details
The vector of magnetic flux values, i.e. the first value should be 0, the rest are strictly ascending.
Dependencies
To use this option, check the box for the option Magnetizing reactance and check the box Magnetic saturation.
| Default value |
|
| Program usage name |
|
| Evaluatable |
Yes |
# Zero sequence reactance, pu — zero-sequence reactance
Details
The reactance of the zero sequence in the O.E. Value must be greater than or equal to the magnetic flux losses of the primary winding.
Dependencies
To use this parameter, set for the parameter Core type meaning Three-phase three-limb.
| Default value |
|
| Program usage name |
|
| Evaluatable |
Yes |
Main
# Tap control — description missing
Details
description missing
| Default value |
|
| Program usage name |
|
| Evaluatable |
No |
# Minimum tap position — description missing
Details
description missing
| Default value |
|
| Program usage name |
|
| Evaluatable |
Yes |
# Maximum tap position — description missing
Details
description missing
| Default value |
|
| Program usage name |
|
| Evaluatable |
Yes |
# Voltage step per tap, pu — description missing
Details
description missing
| Default value |
|
| Program usage name |
|
| Evaluatable |
Yes |