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
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Three-Winding Transformer (Three-Phase) Path in the library: |
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Two-Winding Transformer (Three-Phase) Path in the library: |
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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:
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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:
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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:
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Lower resistance for the zero sequence current component, that is, between the line and the neutral, in the case of an unbalanced load.
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Greater heat dissipation.
The equations
Three-core core
This block is implemented in the magnetic field using blocks Nonlinear Reluctance, Winding and Eddy Current.
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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.:
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— the number of turns of the primary winding.
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— the number of turns of the first secondary winding.
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— the number of turns of the second secondary winding.
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— shunt magnetizing inductance.
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— zero-sequence inductance.
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— the scattering inductance of the primary winding.
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— the scattering inductance of the first secondary winding.
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— the scattering inductance of the second secondary winding.
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— shunting magnetizing resistance.
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— magnetizing resistance between phases
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— zero sequence resistance coefficient
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— leakage resistance of the primary winding
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— leakage resistance of the first secondary winding
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— leakage resistance of the second secondary winding
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— the conductivity of the eddy current loop
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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.
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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.:
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The conclusion follows from this:
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Ports
Non-directional
~1 — terminals of the primary winding
electricity
Three-phase electrical port, corresponds to phase terminals , and the primary winding.
n1 — neutral pass:Q[<br>] electricity
The electrical port connected to the neutral of the primary winding.
Dependencies
To use this port, set the Primary winding connection type parameter to Wye with neutral port.
~2 — terminals of the first secondary winding
electricity
Three-phase electrical port, corresponds to phase terminals , and the first secondary winding.
n2 — neutral pass:Q[<br>] electricity
The electrical port connected to the neutral of the first secondary winding.
Dependencies
To use this port, set the First secondary connection type parameter to Wye with neutral port.
~3 — terminals of the second secondary winding
electricity
Three-phase electrical port, corresponds to phase terminals , and the second secondary winding.
n3 — neutral pass:Q[<br>] electricity
The electrical port connected to the neutral of the second secondary winding.
Dependencies
To use this port, set the Second secondary connection type parameter to Wye with neutral port.
Parameters
Main
Number of windings — switching between two- and three-winding transformer
Two (by default) | Three
Switching between a two- and three-winding transformer.
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Two— the unit simulates a two-winding transformer. -
Three— the unit simulates a three-winding transformer.
Rated apparent power, V*A — rated total power
100e6 In*A (default)
The rated power passing through the transformer. The value must be greater than 0.
Rated electrical frequency — rated electrical frequency
50 Hz (default)
The nominal or nominal frequency of the AC network to which the transformer is connected. The value must be greater than 0.
Primary winding connection type — configuration of the primary winding
Wye with floating neutral (default) | Wye with neutral port | Wye with grounded neutral | Delta 1 o’clock | Delta 11 o’clock
The type of primary winding.
Primary rated voltage — RMS mains voltage applied to the primary winding
4160 (default) | positive scalar
RMS linear voltage applied to the primary winding under normal operating conditions. The value must be greater than 0.
Secondary winding connection type — configuration of the first secondary winding
Wye with floating neutral (default) | Wye with neutral port | Wye with grounded neutral | Delta 1 o’clock | Delta 11 o’clock
The type of the first secondary winding.
Secondary rated voltage, V is the RMS mains voltage applied to the first secondary winding of
4160 (default) | positive scalar
RMS linear voltage applied to the first secondary winding under normal operating conditions. The value must be greater than 0.
Tertial winding connection type — configuration of the second secondary winding
Wye with floating neutral (default) | Wye with neutral port | Wye with grounded neutral | Delta 1 o’clock | Delta 11 o’clock
The type of the second secondary winding.
Nominal rated voltage, V — RMS mains voltage applied to the second secondary winding
4160 (default) | positive scalar
RMS linear voltage applied to the second secondary winding under normal operating conditions. The value must be greater than 0.
Core type — pass core type:q[<br>] Three-phase three-limb (default) | Three-phase five-limb
The type of core.
Impedances
Primary winding resistance, pu — primary winding resistance, O.E.
0.01 (default) | positive scalar
The resistance of the primary winding, i.e. the value must be greater than 0.
First secondary winding resistance, pu — resistance of the first secondary winding, O.E.
0.01 (default) | positive scalar
Resistance of the first secondary winding. The value must be greater than 0.
Second secondary winding resistance, pu — resistance of the second secondary winding, O.E.
0.01 (default) | positive scalar
Resistance of the second secondary winding. The value must be greater than 0.
Leakage reactance — accounting for magnetic flux losses.
Exclude (by default) | Include
Enabling the simulation of magnetic flux losses.
Primary leakage reactance, pu — magnetic resistance of the primary winding, O.E.
0.001 (default) | positive scalar
Magnetic flux losses in the primary winding, i.e. the value must be greater than 0.
Dependencies
To use this parameter, set the Leakage reactivity parameter to Include.
First secondary leakage reactance, pu — magnetic resistance of the first secondary winding, O.E.
0.001 (default) | positive scalar
Magnetic flux losses in the first secondary winding, i.e. the value must be greater than 0.
Dependencies
To use this parameter, set the Leakage reactivity parameter to Include.
Second secondary leakage reactance, pu — magnetic resistance of the second secondary winding, O.E.
0.001 (default) | positive scalar
Magnetic flux losses in the second secondary winding, i.e. the value must be greater than 0.
Dependencies
To use this parameter, set the Leakage reactivity parameter to Include.
Magnetizing resistance — accounting for the magnetization resistance of
Exclude (by default) | Include
Enabling the simulation of the magnetization resistance in the transformer core.
Shunt magnetizing resistance, pu is the active resistance of the magnetization branch, i.e.
500 (by default) | positive scalar
The active resistance of the magnetization branch, i.e., the value must be greater than 0.
Dependencies
To use this parameter, set the Magnetizing resistance parameter to Include.
Magnetizing reactivity — accounting for magnetic effects
Exclude (by default) | Include
Enabling the simulation of the magnetic effects of the transformer core.
Magnetic saturation representation — representation of magnetic saturation
None (by default) | Lookup table (phi versus i)
Choose whether and how to represent the magnetic saturation.
Dependencies
To use this parameter, set the Magnetizing reactivity parameter to Include.
Current vector (pu), i is the vector of current values, O.e
[0, .002, 1, 2] (default)
The vector of current values, i.e. the first value should be 0, the rest are strictly ascending.
Dependencies
To use this parameter, set the Magnetizing reactivity parameter to Include and for the Magnetic saturation representation parameter, the value Lookup table (phi versus i).
Magnetic flux vector (pu), phi — vector of flow values, O.e
[0, 1.2, 1.5, 1.51] ( by default)
The vector of magnetic flux values, i.e. the first value should be 0, the rest are strictly ascending.
Dependencies
To use this parameter, set the Magnetizing reactivity parameter to Include and for the Magnetic saturation representation parameter, the value Lookup table (phi versus i).
Shunt magnetizing reactance, pu — reactance of the magnetization branch, O.E.
500 (by default) | positive scalar
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 parameter, set the Magnetizing reactivity parameter to Include and for the Magnetic saturation representation parameter, the value Lookup table (phi versus i).
Zero sequence reactance, pu — reactance of the zero sequence
0.5 (default) | positive scalar
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 the Core type parameter to Three-phase three-limb.