Documentation

# Converter (Three-Phase)

Controller-driven bidirectional AC/DC three-arm converter

• Library:
• Simscape / Electrical / Semiconductors & Converters / Converters

## Description

The Converter (Three-Phase) block models a three-arm converter circuit that connects a three-phase AC network to a DC network.

Each component in the three-arm circuit is the same switching device, which you specify using an option on the Converter (Three-Phase) block dialog box. The switching devices that you can specify are implementations of blocks in the Simscape > Electrical > Semiconductors & Converters > Semiconductors library.

The figure shows the equivalent circuit for a converter with fully controlled switching devices (e.g. IGBTs, GTOs).

The figure shows the equivalent circuit for a converter with partially controlled switching devices (e.g. thyristors).

Control the gate ports of the six switching devices via an input to port G on the Converter (Three-Phase) block:

1. Multiplex all six gate signals into a single vector with a Six-Pulse Gate Multiplexer block.

2. Connect the output of the Six-Pulse Gate Multiplexer block to the Converter (Three-Phase) block G port.

You can specify an integral protection diode for each switching device. An integral diode protects the semiconductor device by providing a conduction path for reverse current. An inductive load can produce a high reverse-voltage spike when the semiconductor device suddenly switches off the voltage supply to the load.

The table shows you how to set the Integral protection diode parameter based on your goals.

GoalValue to SelectBlock Behavior
Prioritize simulation speed.`Protection diode with no dynamics`The block includes an integral copy of the Diode block. To parameterize the internal Diode block, use the Protection parameters.
Precisely specify reverse-mode charge dynamics.`Protection diode with charge dynamics`The block includes an integral copy of the dynamic model of the Diode block. To parameterize the internal Diode block, use the Protection parameters.

You can include a snubber circuit, consisting of a resistor and capacitor connected in series, for each switching device. Snubber circuits protect switching devices against high voltages that inductive loads produce when the device turns off the voltage supply to the load. Snubber circuits also prevent excessive rates of change of current when a switching device turns on.

## Ports

### Conserving

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Vector input port associated with the gate terminals of the switching devices. Connect this port to a Six-Pulse Gate Multiplexer block.

Electrical conserving port associated with the DC positive terminal

Electrical conserving port associated with the DC negative terminal

## Parameters

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Converter switching device. The default value is ```Ideal Semiconductor Switch```.

The switching devices you can select are:

#### Dependencies

Multiple additional parameters will become visible depending on the choice of the specific switching device.

### Switching Devices: GTO

For more information, see GTO.

The parameters for this switching device will be visible only if you select it in the Switching device parameter.

Minimum voltage required across the anode and cathode block ports for the gradient of the device i-v characteristic to be 1/Ron, where Ron is the value of On-state resistance.

Rate of change of voltage versus current above the forward voltage.

Anode-cathode conductance when the device is off. The value must be less than 1/R, where R is the value of On-state resistance.

Gate-cathode voltage threshold. The device turns on when the gate-cathode voltage is above this value.

Gate-cathode voltage threshold. The device turns off when the gate-cathode voltage is below this value.

Current threshold. The device stays on when the current is above this value, even when the gate-cathode voltage falls below the gate trigger voltage.

### Switching Devices: Ideal Semiconductor Switch

For more information, see Ideal Semiconductor Switch.

The parameters for this switching device will be visible only if you select it in the Switching device parameter.

Anode-cathode resistance when the device is on.

Anode-cathode conductance when the device is off. The value must be less than 1/R, where R is the value of On-state resistance.

Gate-cathode voltage threshold. The device turns on when the gate-cathode voltage is above this value.

### Switching Devices: IGBT

For more information, see IGBT (Ideal, Switching).

The parameters for this switching device will be visible only if you select it in the Switching device parameter.

Minimum voltage required across the collector and emitter block ports for the gradient of the diode i-v characteristic to be 1/Ron, where Ron is the value of On-state resistance.

Collector-emitter resistance when the device is on.

Collector-emitter conductance when the device is off. The value must be less than 1/R, where R is the value of On-state resistance.

Gate-emitter voltage at which the device turns on.

### Switching Devices: MOSFET

For more information, see MOSFET (Ideal, Switching).

The parameters for this switching device will be visible only if you select it in the Switching device parameter.

Drain-source resistance when the device is on.

Drain-source conductance when the device is off. The value must be less than 1/R, where R is the value of On-state resistance.

Gate-source voltage threshold. The device turns on when the gate-source voltage is above this value.

### Switching Devices: Thyristor

The parameters for this switching device will be visible only if you select it in the Switching device parameter.

For more information, see Thyristor (Piecewise Linear).

Forward voltage at which the device turns on.

Anode-cathode resistance when the device is on.

Anode-cathode conductance when the device is off. The value must be less than 1/R, where R is the value of On-state resistance.

Gate-cathode voltage threshold. The device turns on when the gate-cathode voltage is above this value.

Current threshold. The device stays on when the current is above this value, even when the gate-cathode voltage falls below the gate trigger voltage.

### Switching Devices: Averaged Switch

The parameter for this switching device will be visible only if you select it in the Switching device parameter.

### Note

If you select this mode, the value of the gate signals must be between `0` and `1`.

Anode-cathode resistance when the device is on.

### Integral Diodes

Integral protection diode for each switching device.

The diodes you can select are:

• ```Protection diode with no dynamics```

• ```Protection diode with charge dynamics```

### Note

If you select `Averaged Switch` for the Switching Device parameter in the Switching Device setting, this parameter is not visible and ```Protection diode with no dynamics``` is automatically selected.

Minimum voltage required across the `+` and `-` block ports for the gradient of the diode I-V characteristic to be 1/Ron, where Ron is the value of On resistance.

#### Dependencies

This parameter is visible only when the Integral protection diode parameter is set to `Protection diode with no dynamics` or `Protection diode with charge dynamics`.

Rate of change of voltage versus current above the Forward voltage.

#### Dependencies

This parameter is visible only when the Integral protection diode parameter is set to `Protection diode with no dynamics` or `Protection diode with charge dynamics`.

Conductance of the reverse-biased diode.

#### Dependencies

This parameter is visible only when the Integral protection diode parameter is set to `Protection diode with no dynamics` or `Protection diode with charge dynamics`.

Diode junction capacitance.

#### Dependencies

This parameter is visible only when the Integral protection diode parameter is set to `Protection diode with charge dynamics`.

Peak reverse current measured by an external test circuit. This value must be less than zero. The default value is `-235` `A`.

#### Dependencies

This parameter is visible only when the Integral protection diode parameter is set to `Protection diode with 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 Integral protection diode parameter is set to `Protection diode with 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 Integral protection diode parameter is set to `Protection diode with 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 Integral protection diode parameter is set to `Protection diode with 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 Integral protection diode parameter is set to `Protection diode with 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 Integral protection diode parameter is set to `Protection diode with 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 Integral protection diode parameter is set to `Protection diode with charge dynamics` and the Reverse recovery time parameterization parameter is set to `Specify reverse recovery charge`.

For more information on these parameters, see Diode.

### Snubbers

Snubber for each switching device:

• `None` - This is the default value.

• `RC snubber`

Snubber resistance.

#### Dependencies

This parameter is visible only when the Snubber parameter is set to ```RC snubber```.

Snubber capacitance.

#### Dependencies

This parameter is visible only when the Snubber parameter is set to ```RC snubber```.

## Extended Capabilities

### C/C++ Code GenerationGenerate C and C++ code using Simulink® Coder™.

#### 10 Ways to Speed Up Power Conversion Control Design with Simulink

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