# Three-Winding Nonlinear Transformer

Single-phase nonlinear three-winding transformer

**Library:**Simscape / Electrical / Passive / Transformers

## Description

The Three-Winding Nonlinear Transformer block represents a single-phase, nonlinear, three-winding transformer with a nonideal core. A core may be nonideal due to its magnetic properties or dimensions. This figure shows the equivalent circuit topology:

where:

*R1*is the primary winding resistance.*L1*is the primary leakage inductance.*R2*is the first secondary winding resistance.*L2*is the first secondary leakage inductance.*R3*is the second secondary winding resistance.*L3*is the second secondary leakage inductance.*Rm*is the magnetization resistance.*Lm*is the magnetization inductance.

The block provides the following parameterization options for the nonlinear magnetization inductance:

`Single inductance (linear)`

`Single saturation point`

`Magnetic flux versus current characteristic`

`Magnetic flux density versus magnetic field strength characteristic`

`Magnetic flux density versus magnetic field strength characteristic with hysteresis`

For more information, see the Nonlinear Inductor block reference page.

## Ports

### Conserving

`1+`

— Line 1 positive terminal

electrical

Electrical conserving port associated with the positive terminal of line 1.

`1-`

— Line 1 negative terminal

electrical

Electrical conserving port associated with the negative terminal of line 1.

`2+`

— Line 2 positive terminal

electrical

Electrical conserving port associated with the positive terminal of line 2.

`2-`

— Line 2 negative terminal

electrical

Electrical conserving port associated with the negative terminal of line 2.

`3+`

— Line 3 positive terminal

electrical

Electrical conserving port associated with the positive terminal of line 3.

`3-`

— Line 3 negative terminal

electrical

Electrical conserving port associated with the negative terminal of line 3.

## Parameters

### Main

`Primary number of turns`

— Winding 1 primary turns number

`100`

(default) | positive scalar integer

Number of turns of wire on the first primary winding of the transformer.

`First secondary number of turns`

— Winding 2 turns number

`200`

(default) | positive scalar integer

Number of turns of wire on the first secondary winding of the transformer.

`Second secondary number of turns`

— Winding 3 turns number

`200`

(default) | positive scalar integer

Number of turns of wire on the second secondary winding of the transformer.

`Primary winding resistance`

— Winding 1 resistance

`0.01`

`Ohm`

(default) | nonnegative scalar

Resistance for *R1*, which represents the power loss
of the primary winding.

`Primary leakage inductance`

— Winding 1 leakage inductance

`0.0001`

`H`

(default) | nonnegative scalar

Inductance for *L1*, which represents the magnetic flux loss of the
primary winding.

`First secondary winding resistance`

— Winding 2 resistance

`0.01`

`Ohm`

(default) | nonnegative scalar

Resistance for *R2*, which represents the power loss
of the first secondary winding.

`First secondary leakage inductance`

— Winding 2 leakage inductance

`0.0001`

`H`

(default) | nonnegative scalar

Inductance for *L2*, which represents the magnetic flux loss of the
first secondary winding.

`Second secondary winding resistance`

— Winding 3 resistance

`0.01`

`Ohm`

(default) | nonnegative scalar

Resistance for *R3*, which represents the power loss
of the second secondary winding.

`Second secondary leakage inductance`

— Winding 3 leakage inductance

`0.0001`

`H`

(default) | nonnegative scalar

Inductance for *L3*, which represents the magnetic flux loss of the
second secondary winding.

### Magnetization

`Magnetization resistance`

— Magnetization resistance

`100`

`Ohm`

(default)

Resistance for *Rm*, which represents the magnetic losses in the
transformer core.

`Magnetization inductance parameterized by`

— Nonlinear magnetization inductance parameterization

```
Single saturation
point
```

(default) | `Single inductance (linear)`

| ```
Magnetic flux versus current
characteristic
```

| ```
Magnetic flux density versus field strength
characteristic
```

| ```
Magnetic flux density versus field strength
characteristic with hysteresis
```

Method of the nonlinear magnetization inductance parameterization:

`Single inductance (linear)`

— Provide the unsaturated inductance value.`Single saturation point`

— Provide the values for the unsaturated and saturated inductances, as well as saturation magnetic flux. This is the default option.`Magnetic flux versus current characteristic`

— Provide the current vector and the magnetic flux vector, and then populate the magnetic flux versus current lookup table.`Magnetic flux density versus field strength characteristic`

— Provide the values for effective core length, cross-sectional area, magnetic field strength vector and the magnetic flux density vector, and then populate the magnetic flux density versus magnetic field strength lookup table.`Magnetic flux density versus field strength characteristic with hysteresis`

— Define magnetic flux density as a function or both the current value and the history of the field strength by providing the number of turns, the effective core length and cross-sectional area, the initial anhysteretic B-H curve gradient, the magnetic flux density and field strength at a certain point on the B-H curve, the coefficient for the reversible magnetization, the bulk coupling coefficient, and the inter-domain coupling factor.

`Unsaturated inductance`

— Unsaturated inductance

`4e-2`

`H`

(default)

Value of inductance used when the magnetization inductance *Lm* is
operating in its linear region.

#### Dependencies

To enable this parameter, set the **Magnetization inductance parameterized
by** parameter to ```
Single inductance
(linear)
```

or ```
Single saturation
point
```

.

`Saturated inductance`

— Saturated inductance

`1e-2`

`H`

(default)

Value of inductance used when the magnetization inductance *Lm* is
operating beyond its saturation point.

#### Dependencies

To enable this parameter, set the **Magnetization
inductance parameterized by** parameter to
`Single saturation point`

.

`Saturation magnetic flux`

— Saturation magnetic flux

`1.6e-04`

`Wb`

(default)

Value of magnetic flux at which the magnetization inductance *Lm*
saturates.

#### Dependencies

To enable this parameter, set the **Magnetization
inductance parameterized by** parameter to
`Single saturation point`

.

`Current vector, i`

— Current data

`[0, .4, .8, 1.2, 1.6, 2]`

`A`

(default)

Current data used to populate the magnetic flux versus current lookup table.

#### Dependencies

To enable this parameter, set the **Magnetization
inductance parameterized by** parameter to
```
Magnetic flux versus current
characteristic
```

.

`Magnetic flux vector, phi`

— Magnetic flux vector

```
[0, .161, .25, .284, .295, .299] .*
1e-3
```

`Wb`

(default)

Magnetic flux data used to populate the magnetic flux versus current lookup table.

#### Dependencies

To enable this parameter, set the **Magnetization
inductance parameterized by** parameter to
```
Magnetic flux versus current
characteristic
```

.

`Magnetic field strength vector, H`

— Magnetic field strength vector

`[0, 200, 400, 600, 800, 1000]`

`A/m`

(default)

Magnetic field strength data used to populate the magnetic flux density versus magnetic field strength lookup table.

#### Dependencies

To enable this parameter, set the **Magnetization
inductance parameterized by** parameter to
```
Magnetic flux density versus field strength
characteristic
```

.

`Magnetic flux density vector, B`

— Magnetic flux density vector

`[0, .81, 1.25, 1.42, 1.48, 1.49]`

`T`

(default)

Magnetic flux density data used to populate the magnetic flux density versus magnetic field strength lookup table.

#### Dependencies

To enable this parameter, set the **Magnetization
inductance parameterized by** parameter to
```
Magnetic flux density versus field strength
characteristic
```

.

`Effective length`

— Effective length

`0.2`

`m`

(default)

Effective core length, also defined as the average distance of the magnetic path around the transformer core.

#### Dependencies

To enable this parameter, set the **Magnetization
inductance parameterized by** parameter to
```
Magnetic flux density versus field strength
characteristic
```

.

`Effective cross-sectional area`

— Effective cross-sectional area

`2e-4`

`m^2`

(default)

Effective core cross-sectional area, also defined as the average area of the magnetic path around the transformer core.

#### Dependencies

**Magnetization
inductance parameterized by** parameter to
```
Magnetic flux density versus field strength
characteristic
```

.

`Anhysteretic B-H gradient when H is zero`

— Anhysteretic B-H gradient around zero field strength

`0.005`

`m*T/A`

(default)

Gradient of the anhysteretic B-H curve around zero field strength. Set this parameter to the average gradient of the positive-going and negative-going hysteresis curves.

#### Dependencies

To enable this parameter, set the **Magnetization
inductance parameterized by** parameter to
```
Magnetic flux density versus field strength
characteristic with hysteresis
```

.

`Flux density point on anhysteretic B-H curve`

— Flux density point on anhysteretic B-H curve

`1.49`

`T`

(default)

Specify a point on the anhysteretic curve by providing its flux density value. Picking a point at high field strength where the positive-going and negative-going hysteresis curves align is the most accurate option.

#### Dependencies

To enable this parameter, set the **Magnetization
inductance parameterized by** parameter to
```
Magnetic flux density versus field strength
characteristic with hysteresis
```

.

`Corresponding field strength`

— Corresponding field strength

`1000`

`A/m`

(default)

Corresponding field strength for the point defined by the **Flux density point
on anhysteretic B-H curve** parameter.

#### Dependencies

To enable this parameter, set the **Magnetization
inductance parameterized by** parameter to
```
Magnetic flux density versus field strength
characteristic with hysteresis
```

.

`Coefficient for reversible magnetization, c`

— Coefficient for reversible magnetization

`0.1`

(default)

Proportion of the magnetization that is reversible. The value should be greater than zero and less than one.

#### Dependencies

**Magnetization
inductance parameterized by** parameter to
```
Magnetic flux density versus field strength
characteristic with hysteresis
```

.

`Bulk coupling coefficient, K`

— Bulk coupling coefficient

`200`

`A/m`

(default)

Jiles-Atherton parameter that primarily controls the field strength magnitude at which the B-H curve crosses the zero flux density line.

#### Dependencies

**Magnetization
inductance parameterized by** parameter to
```
Magnetic flux density versus field strength
characteristic with hysteresis
```

.

`Inter-domain coupling factor, alpha`

— Inter-domain coupling factor

`1e-4`

(default)

Jiles-Atherton parameter that primarily affects the points at which the B-H curves intersect the zero field strength line. Typical values are in the range of 1e-4 to 1e-3.

#### Dependencies

**Magnetization
inductance parameterized by** parameter to
```
Magnetic flux density versus field strength
characteristic with hysteresis
```

.

`Interpolation option`

— Interpolation option

`Linear`

(default) | `Smooth`

Lookup table interpolation option. Select one of the following interpolation methods:

`Linear`

— Select this option to get the best performance.`Smooth`

— Produce a continuous curve with continuous first-order derivatives.

For more information on interpolation algorithms, see the PS Lookup Table (1D) block reference page.

#### Dependencies

To enable this parameter, set the **Magnetization
inductance parameterized by** parameter to
```
Magnetic flux versus current
characteristic
```

or ```
Magnetic flux
density versus field strength characteristic
```

.

### Initial Conditions

`Primary leakage inductance initial current`

— Primary leakage inductance initial current

`0`

`A`

(default)

Value of the current through the primary leakage inductance *L1* at
time zero.

`First secondary leakage inductance initial current`

— First secondary leakage inductance initial current

`0`

`A`

(default)

Value of the current through the first secondary leakage inductance
*L2* at time zero.

`Second secondary leakage inductance initial current`

— Second secondary leakage inductance initial current

`0`

`A`

(default)

Value of the current through the second secondary leakage inductance
*L3* at time zero.

`Specify magnetization inductance initial state by`

— Initial state specification option

`Current`

(default) | `Magnetic flux`

Initial state specification.

`Current`

— Specify the initial state of the magnetization inductance*Lm*by the initial current.`Magnetic flux`

— Specify the initial state of the magnetization inductance*Lm*by the magnetic flux.

#### Dependencies

To enable this parameter, on the
**Magnetization** setting, set the
**Magnetization inductance parameterized by**
parameter to:

`Single inductance (linear)`

`Single saturation point`

`Magnetic flux versus current characteristic`

`Magnetic flux density versus field strength characteristic`

`Magnetization inductance initial current`

— Magnetization inductance initial current

`0`

`A`

(default)

Initial current value used to calculate the value of magnetic flux within the
magnetization inductance *Lm* at time zero. This is the
current passing through the magnetization inductance
*Lm*. Total magnetization current consists of
current passing through the magnetization resistance
*Rm* and current passing through the magnetization
inductance *Lm*.

#### Dependencies

To enable this parameter, set the **Specify magnetization
inductance initial state by** parameter to
`Current`

`Magnetization inductance initial magnetic flux`

— Magnetization inductance initial magnetic flux

`0`

`Wb`

(default)

Value of the magnetic flux in the magnetization inductance *Lm* at time
zero.

#### Dependencies

To enable this parameter, set the **Specify magnetization
inductance initial state by** parameter to
`Magnetic flux`

`Magnetization inductance initial magnetic flux density`

— Magnetization inductance initial magnetic flux density

`0`

`T`

(default)

Value of magnetic flux density at time zero.

#### Dependencies

To enable this parameter, on the
**Magnetization** setting, set the
**Magnetization inductance parameterized by**
parameter to ```
Magnetic flux density versus field
strength characteristic with hysteresis
```

`Magnetization inductance initial field strength`

— Magnetization inductance initial field strength

`0`

`A/m`

(default)

Value of magnetic field strength at time zero.

#### Dependencies

To enable this parameter, on the
**Magnetization** setting, set the
**Magnetization inductance parameterized by**
parameter to ```
Magnetic flux density versus field
strength characteristic with hysteresis
```

### Parasitics

`Primary leakage inductance parasitic parallel conductance`

— Winding 1 leakage inductance parasitic parallel conductance

`1e-9`

`1/Ohm`

(default) | nonneagative scalar

Small parasitic effects in parallel to the primary leakage inductance
*L1*. A small parallel conductance may be required
for the simulation of some circuit topologies.

`First secondary leakage inductance parasitic parallel conductance`

— Winding 2 leakage inductance parasitic parallel conductance

`1e-9`

`1/Ohm`

(default) | nonneagative scalar

Small parasitic effects in parallel to the first secondary leakage
inductance *L2*. A small parallel conductance may be
required for the simulation of some circuit topologies.

`Second secondary leakage inductance parasitic parallel conductance`

— Winding 3 leakage inductance parasitic parallel conductance

`1e-9`

`1/Ohm`

(default) | nonneagative scalar

Small parasitic effects in parallel to the second secondary leakage
inductance *L3*. A small parallel conductance may be
required for the simulation of some circuit topologies.

## Extended Capabilities

### C/C++ Code Generation

Generate C and C++ code using Simulink® Coder™.

## See Also

**Introduced in R2019b**

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