# Rectifier (Three-Phase)

Uncontrolled three-phase AC to DC voltage

Libraries:
Simscape / Electrical / Semiconductors & Converters / Converters

## Description

The Rectifier (Three-Phase) block models a three-arm diode bridge circuit that converts a three-phase AC voltage to a DC voltage. The figure shows the equivalent circuit for the three-arm diode bridge.

Using the Charge Dynamics tab of the block dialog box, you can choose the type of diode that the three-arm bridge circuit uses. The table shows you how to set the Model dynamics parameter based on your goals.

GoalValue to SelectBlock Behavior
Prioritize simulation speed.`No dynamics`Each arm of the bridge circuit uses a copy of the Diode block. The block dialog box does not display additional parameters.
Precisely specify reverse-mode charge dynamics.`Model charge dynamics`Each arm of the bridge circuit uses a copy of the commutation model of the Diode block. The block dialog box shows parameters relating to the commutation model of the block.

## Ports

### Conserving

expand all

#### Dependencies

To enable this port, set Electrical connection to ```Composite three-phase ports```.

Electrical conserving port associated with a-phase.

#### Dependencies

To enable this port, set Electrical connection to ```Expanded three-phase ports```.

Electrical conserving port associated with b-phase.

#### Dependencies

To enable this port, set Electrical connection to ```Expanded three-phase ports```.

Electrical conserving port associated with c-phase.

#### Dependencies

To enable this port, set Electrical connection to ```Expanded three-phase ports```.

Electrical conserving port associated with the positive terminal

Electrical conserving port associated with the negative terminal

## Parameters

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### Main

Whether to have composite or expanded three-phase ports.

Minimum voltage required across the `+` and `-` ports of each diode for the gradient of the diode i-v characteristic to be 1/Ron, where Ronis the value of On resistance.

Rate of change of voltage versus current above the forward voltage for each diode.

Conductance of each reverse-biased diode.

### Charge Dynamics

Diode charge dynamics. The default value is ```No dynamics```.

The charge dynamics options you can select are:

• `No dynamics`

• `Model charge dynamics`

Diode junction capacitance.

#### Dependencies

This parameter is visible only when the Model dynamics parameter is set to `Model charge dynamics`.

Peak reverse current measured by an external test circuit. This value must be less than zero.

#### Dependencies

This parameter is visible only when the Model dynamics parameter is set to `Model charge dynamics`.

Initial forward current when measuring peak reverse current. This value must be greater than zero.

#### Dependencies

This parameter is visible only when the Model dynamics parameter is set to `Model charge dynamics`.

Rate of change of current when measuring peak reverse current. This value must be less than zero.

#### Dependencies

This parameter is visible only when the Model dynamics parameter is set to `Model charge dynamics`.

Determines how you specify reverse recovery time in the block. The default value is `Specify reverse recovery time directly`.

If you select `Specify stretch factor` or `Specify reverse recovery charge`, you specify a value that the block uses to derive the reverse recovery time. For more information on these options, see How the Block Calculates TM and Tau.

#### Dependencies

This parameter is visible only when the Model dynamics parameter is set to `Model charge dynamics`.

Interval between the time when the current initially goes to zero (when the diode turns off) and the time when the current falls to less than 10% of the peak reverse current. The value of the Reverse recovery time, trr parameter must be greater than the value of the Peak reverse current, iRM parameter divided by the value of the Rate of change of current when measuring iRM parameter.

#### Dependencies

This parameter is visible only when the Model dynamics parameter is set to `Model charge dynamics` and the Reverse recovery time parameterization parameter is set to `Specify reverse recovery time directly`.

Value that the block uses to calculate Reverse recovery time, trr. This value must be greater than `1`. Specifying the stretch factor is an easier way to parameterize the reverse recovery time than specifying the reverse recovery charge. The larger the value of the stretch factor, the longer it takes for the reverse recovery current to dissipate.

#### Dependencies

This parameter is visible only when the Model dynamics parameter is set to `Model charge dynamics` and the Reverse recovery time parameterization parameter is set to `Specify stretch factor`.

Value that the block uses to calculate Reverse recovery time, trr. Use this parameter if the data sheet for your diode device specifies a value for the reverse recovery charge instead of a value for the reverse recovery time.

The reverse recovery charge is the total charge that continues to dissipate when the diode turns off. The value must be less than $-\frac{{i}^{2}{}_{RM}}{2a},$

where:

• iRM is the value specified for Peak reverse current, iRM.

• a is the value specified for Rate of change of current when measuring iRM.

#### Dependencies

This parameter is visible only when the Model dynamics parameter is set to `Model charge dynamics` and the Reverse recovery time parameterization parameter is set to `Specify reverse recovery charge`.