Duality-Based, 3-Phase 2-Winding Transformer

 

Description

This component represents a mode of a 3-phase, 2-winding transformer, based on the principle of duality.

 

It can be used to model a multi-limb transformer or a bank of single-phase transformers. Several methods of entering transformer core, nonlinearity parameters are available. Optional stray capacitances are also available.

 

More:

Adjusting Saturation Properties

Transformer Magnetic Hysteresis

Input Parameters

ConfigurationConfiguration

 

 Transformer Name

 

Text

 

Just an identifier. A name should be entered here to avoid compilation warnings

 

 

 

 

 

Transformer Core Model

 

 

 

Select from 3 phase bank, 5 limb, 3 limb or 3 limb with zero sequence, to represent the transformer core construction.

 

 

 

 

 

3-Phase Transformer MVA

 

REAL

Constant

The 3-phase apparent power rating of the transformer [MVA].

 

 

 

 

 

Base Operation Frequency

 

REAL

Constant

The base frequency of the electrical system, in which the transformer resides [Hz].

 

 

 

 

 

Total Copper Losses

 

REAL

Constant

Enter the total copper losses based on the transformer MVA [pu].

 

 

 

 

 

% of Copper Loss for Winding 1

 

REAL

Constant

Enter the percentage of copper loss to be placed at winding 1. The remaining percentage will be placed at winding 2 [%].

 

 

 

 

 

Core Eddy Current Losses

 

REAL

Constant

Enter the core eddy current, less the portion of no-load losses, based on the transformer rating. Hysteresis loss may also be added here, if hysteresis is not modeled [%].

 

 

 

 

 

Total Positive Sequence Leakage Reactance

 

REAL

Constant

Total positive sequence leakage reactance, enter it based on transformer base impedance [pu].

 

 

 

 

 

% of Positive Sequence Leakage Reactance for Winding 1

 

REAL

Constant

Percentage of positive sequence leakage for winding 1 [%].

 

 

 

 

 

Leakage Reactance Ratio (Zero/Positive Sequence)

 

REAL

Constant

Enter the ratio of zero sequence over positive sequence leakage reactance.

 

 

 

 

 

Display Details

 

Choice

 

Select Yes or No. Displays MVA and winding voltages near the component.

 

Winding SettingsWinding Settings

 

Open Terminals?

 

Choice

 

Select Yes or No. Select Yes to get access to all transformer terminals.

 

 

 

 

 

Winding # Connection

 

Choice

 

Select the connection type for the specified winding # - Y or D connected.

 

 

 

 

 

Vector Group

 

Choice

 

Select  the transformer vector group.

 

Regardless of RMS winding voltages, winding 1 is the reference winding (Y or D) and the phase shift is imposed on winding 2 (Y or D).

 

 

 

 

 

Y Neutral for Winding #

 

Choice

 

Select Solidly grounded, Ungrounded or External, to represent the type of - connection neutral for the designated winding.

 

 

 

 

 

Winding # Line to Line Voltage (RMS)

 

REAL

Constant

The RMS voltage rating of the corresponding winding # [kV].

 

 

 

 

 

Single Phase Winding # Voltage (RMS)

 

REAL

Constant

Enter the RMS voltage rating across a single, specified winding [kV].

 

 

Magnetization BranchMagnetization Branch

NOTE: See Adjusting Saturation Properties and Transformer Magnetic Hysteresis for more details on these inputs. The parameters in this category are visible based on the settings of choice parameter Magnetization Model.

 

Magnetization Model

 

Choice

 

Select the type of magnetizing branch from Linear, Basic hysteresis, Jiles-Atherton hysteresis, V-I with aspect ratios, B-H with aspect ratios or B-H with dimensions.

 

 

 

 

 

Excitation Current

 

REAL

Constant

Enter the RMS exciting current as a percentage of base current [%].

 

 

 

 

 

Air Core Reactance

 

REAL

Constant

Enter the air core reactance based on transformer base impedance [pu].

 

 

 

 

 

Knee Voltage for Winding-Limb

 

REAL

Constant

Enter the knee point voltage corresponding to saturation curve for winding-limb [pu].

 

 

 

 

 

Loop Width

 

REAL

Constant

Enter the loop width as a percentage of magnetizing current [%].

 

 

 

 

 

Nominal Magnetic Flux Density

 

REAL

Constant

Enter the nominal magnetic flux density corresponding to saturation curve [T].

 

 

 

 

 

# of Saturation Characteristics Points

 

Choice

 

Select the number of points used to represent the saturation curve.

 

 

 

 

 

Excitation Currents Point # (I#)

 

REAL

Constant

Saturation characteristics RMS current [%].

 

 

 

 

 

Domain Flexing Parameter

 

REAL

Constant

This parameter represents the contribution of reversible magnetization process.

 

 

 

 

 

Domain Pinning Parameter

 

REAL

Constant

This parameter has a direct impact on the width of the loop [A/m].

 

 

 

 

 

Parameter to Adjust K with M

 

REAL

Constant

This parameter adjusts domain pinning parameter with magnetization for better representation of shoulder area.

 

 

 

 

 

Interdomain Coupling

 

REAL

Constant

This is a mean field parameter corresponding to the interdomain coupling. It is typically determined experimentally.

 

 

 

 

 

Saturated Anhysteretic Magnetization

 

REAL

Constant

This parameter is typically known for a particular material and thus can be obtained from data sheets, etc. [A/m].

 

 

 

 

 

Coefficient # of Anhysteretic Curve

 

REAL

Constant

Coefficient # of the improved anhysteretic function. This function offers more flexibility for obtaining a better overall shape of the simulated B–H loop compared to the Langevin function.

 

 

 

 

 

Magnetic Field Intensities Point # (H#)

 

REAL

Constant

Saturation characteristics magnetic field intensity H [A/m].

 

 

 

 

 

Magnetic Field Intensities Point # (B#)

 

REAL

Constant

Saturation characteristics magnetic flux density B [T].

 

 

 

 

 

Remanent Flux for Core #

 

REAL

Constant

Enter the remanent flux as a per-unit value of the peak flux at rated voltage [pu].

 

 

 

 

 

V-I Point in Linear Region - Voltage

 

REAL

Constant

Typically the smallest voltage in the RMS V–I saturation curve [pu].

 

 

 

 

 

V-I Point in Linear Region - Excitation Current

 

REAL

Constant

Typically the current corresponding to the smallest voltage in the RMS V–I saturation curve [%].

 

 

 

 

 

Voltages Point # (V#)

 

REAL

Constant

Saturation characteristics RMS voltage [pu].

 

 

Core GeometryCore Geometry

NOTE: The parameters in this category are enabled based on the settings of choice parameters Magnetization Model and Transformer Core Model.

 

Aspect Ratio Yoke/Winding limb Length (ly/lw)

 

REAL

Constant

Enter the ratio of the effective length of the yoke over the effective length of the winding limb.

 

 

 

 

 

Aspect Ratio Yoke/Winding limb Area (sy/sw)

 

REAL

Constant

Enter the ratio of the cross sectional area of the yoke over the cross sectional area of the winding limb.

 

 

 

 

 

Aspect Ratio Yoke/Outer limb Length (ly/lo)

 

REAL

Constant

Enter the ratio of the effective length of the yoke over the effective length of the outer limb.

 

 

 

 

 

Aspect Ratio Yoke/Outer limb Area (sy/so)

 

REAL

Constant

Enter the ratio of the cross sectional area of the yoke over the cross sectional area of the outer limb.

 

 

 

 

 

Length of Winding Limb

 

REAL

Constant

Enter the effective length of the winding limb [m].

 

 

 

 

 

Length of Yoke

 

REAL

Constant

Enter the effective length of the yoke [m].

 

 

 

 

 

Length of Outer Limb

 

REAL

Constant

Enter the effective length of the outer limb [m].

 

 

 

 

 

Area of Winding Limb

 

REAL

Constant

Enter the cross sectional area of the winding limb [m2].

 

 

 

 

 

Area of Yoke

 

REAL

Constant

Enter the cross sectional area of the yoke [m2].

 

 

 

 

 

Area of Outer Limb

 

REAL

Constant

Enter the cross sectional area of the outer limb [m2] .

 

 

Tap SettingsTap Settings

 

Tap Changer on Winding

 

Choice

 

Select the winding number (1 or 2) on which to place the on-line tap changer.

 

 

 

 

 

Tap Value Entry

 

Choice

 

Select Internal or External (classical), as the method of entering the tap value.

 

 

 

 

 

Tap Value

 

REAL

Variable

Enter the tap value as a real number or variable name [pu].

 

 

 

 

 

Leakage Reactance Correction

 

Choice

 

Select Disabled or Enabled. Enable if per-unit value of leakage reactance depends on the tap value and correction is required. Disable if leakage reactance remains constant as a per-unit value (classical).

 

 

 

 

 

Maximum Tap Value

 

REAL

Constant

Enter the maximum tap value [pu].

 

 

 

 

 

Total Positive Sequence Leakage Reactance (Maximum Tap)

 

REAL

Constant

Enter the leakage reactance at maximum tap based on transformer base impedance [pu].

 

 

 

 

 

Leakage Reactance Ratio (Zero/Positive Sequence) (Maximum Tap)

 

REAL

Constant

Enter the ratio of zero sequence leakage reactance over positive sequence leakage reactance at maximum tap.

 

 

 

 

 

Minimum Tap Value

 

REAL

Constant

Enter the minimum tap value [pu].

 

 

 

 

 

Total Positive Sequence Leakage Reactance (Minimum Tap)

 

REAL

Constant

Enter the leakage reactance at minimum tap based on transformer base impedance [pu].

 

 

 

 

 

Reactance Ratio (Zero/Positive Sequence) (Minimum Tap)

 

REAL

Constant

Enter the ratio of zero sequence leakage reactance over positive sequence leakage reactance at minimum tap.

 

 

Stray CapacitancesStray Capacitances

NOTE: If no name is specified, these output signals will not be monitored.

 

 Shunt Capacitance at Winding #?

 

Choice

 

Select Yes to place a shunt capacitance from winding # terminal to ground.

 

 

 

 

 

Capacitance Between Winding 1 & 2?

 

Choice

 

Select Yes to place a capacitance between winding 1 and 2 terminals.

 

 

 

 

 

Shunt Capacitance at Winding #

 

REAL

Constant

Enter the corresponding capacitance value [mF].

 

 

 

 

 

Capacitance Between Winding 1 & 2

 

REAL

Output

Enter the corresponding capacitance value [mF].

 

 

Internal OutputsInternal Outputs

 

Name for Flux Density of Winding Limb #

 

REAL

Output

Enter name for flux density of winding limb # [T].

 

 

 

 

 

Name for Flux Density of Yoke #-#

 

REAL

Output

Enter name for flux density of yoke #-# [T].

 

 

 

 

 

Name for Flux Density of Outer Limb #

 

REAL

Output

Enter name for flux density of outer limb # [T].

 

 

 

 

 

Name for Flux Linkage of Winding Limb #

 

REAL

Output

Enter name for flux linkage of winding limb # [pu].

 

 

 

 

 

Name for Flux Linkage of Yoke #-#

 

REAL

Output

Enter name for flux linkage of yoke #-# [pu].

 

 

 

 

 

Name for Flux Linkage of Outer Limb #

 

REAL

Output

Enter name for flux linkage of outer limb # [pu].

 

 

 

 

 

Name for Magnetic Field Intensity of Winding Limb #

 

REAL

Output

Enter name for magnetic field intensity of winding limb # [A/m].

 

 

 

 

 

Name for Magnetic Field Intensity of Yoke #-#

 

REAL

Output

Enter name for magnetic field intensity of yoke #-# [A/m].

 

 

 

 

 

Name for Magnetic Field Intensity of Outer Limb #

 

REAL

Output

Enter name for magnetic field intensity of outer limb # [A/m].

 

 

 

 

 

Name for Magnetizing Current of Winding Limb #

 

REAL

Output

Enter name for magnetizing current of winding limb # [%].

 

 

 

 

 

Name for Magnetizing Current of Yoke #-#

 

REAL

Output

Enter name for magnetizing current of yoke #-# [%].

 

 

 

 

 

Name for Magnetizing Current of Outer Limb #

 

REAL

Output

Enter name for magnetizing current of outer limb # [%].

 

 

 

 

 

Name for Winding # Current of Winding Limb #

 

REAL

Output

Enter name for winding # current of winding limb # [kA].