# Center-Tapped Transformer

Single-phase center-tapped transformer

Since R2023b

Libraries:
Simscape / Electrical / Passive / Transformers

## Description

The Center-Tapped Transformer block implements a center-tapped transformer. In switch-mode power supplies applications, you often use a center-tapped transformer inside a full-wave rectifier, which needs the entire DC output from the AC input.

The two electrical networks that connect to the primary and secondary windings of the Center-Tapped Transformer block must each have their own Electrical Reference block. Normally, you also connect the center tap of the secondary winding to an Electrical Reference block.

### Equations

This figure shows the equivalent circuit of the Center-Tapped Transformer block when you set the Modeling option parameter to `Ideal`:

This figure shows the equivalent circuit of the Center-Tapped Transformer block when you set the Modeling option parameter to `Non-Ideal`:

You must determine the relation between the electrical domain parameters from the block mask and the magnetic domain parameters used in the equivalent circuit model:

• n is the value of the Winding ratio parameter.

• L1 is the value of the Primary leakage inductance parameter.

• Rm is the value of the Magnetization resistance parameter.

• Lm is the value of the Magnetization inductance parameter.

• T is the value of the Center tap position (0~1) parameter.

• L2 is the value of the Secondary leakage inductance parameter.

• Rw2 is the value of the Secondary winding resistance parameter.

• ${R}_{1}=\frac{{n}^{2}}{{L}_{1}}$ is the primary winding leakage reluctance.

• $R=\frac{{n}^{2}}{{L}_{m}}$ is the shunt magnetizing resistance.

• ${L}_{eddy}=\frac{{n}^{2}}{{R}_{m}}$ is the conductance of the eddy current loop.

• ${R}_{2}=\frac{{\left(1-T\right)}^{2}+{T}^{2}}{{L}_{2}}$ is the secondary winding leakage reluctance.

• ${R}_{w2p}={R}_{w2}\left(1-T\right)$ is the secondary top winding resistance.

• ${R}_{w2n}={R}_{w2}T$ is the secondary bottom winding resistance.

## Ports

### Conserving

expand all

Electrical conserving port associated with the positive polarity of the primary winding.

Electrical conserving port associated with the negative polarity of the primary winding.

Electrical conserving port associated with the positive polarity of the secondary winding.

Electrical conserving port associated with the negative polarity of the secondary winding.

Electrical conserving port associated with the center tap of the secondary winding.

## Parameters

expand all

Option to model an ideal or non-ideal center-tapped transformer. If you set this parameter to `Non-Ideal`, the block also models the winding, fundamental reluctance, and eddy current.

Winding ratio of the transformer, which is equal to the ratio of the number of primary coil turns to the number of secondary coil turns.

Location of the center tap on the secondary winding.

Series resistance of the primary winding.

#### Dependencies

To enable this parameter, set Modeling option to `Non-Ideal`.

Leakage inductance of the primary winding.

#### Dependencies

To enable this parameter, set Modeling option to `Non-Ideal`.

Series resistance of the secondary winding.

#### Dependencies

To enable this parameter, set Modeling option to `Non-Ideal`.

Leakage inductance of the secondary winding.

#### Dependencies

To enable this parameter, set Modeling option to `Non-Ideal`.

Magnetization resistance of the transformer.

#### Dependencies

To enable this parameter, set Modeling option to `Non-Ideal`.

Magnetization inductance of the transformer.

#### Dependencies

To enable this parameter, set Modeling option to `Non-Ideal`.

## Version History

Introduced in R2023b