Thyristor

Semiconductors / Fundamental Components

The Thyristor block models a thyristor. The I-V characteristic for a thyristor is such that the thyristor turns on if the gate-cathode voltage exceeds the specified gate trigger voltage. The device turns off if the load current falls below the specified holding-current value.

In the on state, the anode-cathode path behaves like a linear
diode with forward-voltage drop, *V _{f}*,
and on-resistance,

In the off state, the anode-cathode path behaves like a linear
resistor with a low off-state conductance, *G _{off}*.

The defining Simscape™ equations for the block are:

if (v > Vf)&&((G>Vgt)||(i>Ih)) i == (v - Vf*(1-Ron*Goff))/Ron; else i == v*Goff; end

where:

*v*is the anode-cathode voltage.*Vf*is the forward voltage.*G*is the gate voltage.*Vgt*is the gate trigger voltage.*i*is the anode-cathode current.*Ih*is the holding current.*Ron*is the on-state resistance.*Goff*is the off-state conductance.

Using the Integral Diode tab of the block dialog box, you can include an integral cathode-anode diode. 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.

Goal | Value to Select | Block Behavior |
---|---|---|

Prioritize simulation speed. | `Protection diode with no dynamics` | The block includes an integral copy of the Diode block. The block dialog box shows parameters relating to the Diode block. |

Precisely specify reverse-mode charge dynamics. | `Protection diode with charge dynamics` | The block includes an integral copy of the Commutation Diode block. The block dialog box shows parameters relating to the Commutation Diode block. |

The block provides four modeling variants. To select the desired
variant, right-click the block in your model. From the context menu,
select **Simscape** > **Block
choices**, and then one of these variants:

**PS Control Port**— Contains a physical signal port that is associated with the gate terminal. This variant is the default.**Electrical Control Port**— Contains an electrical conserving port that is associated with the gate terminal.**PS Control Port | Thermal Port**— Contains a thermal port and a physical signal port that is associated with the gate terminal.**Electrical Control Port | Thermal Port**— Contains a thermal port and an electrical conserving port that is associated with the gate terminal.

The variants of this block without the thermal port do not simulate heat generation in the device.

The variants with the thermal port allow you to model the heat that switching events and conduction losses generate. For numerical efficiency, the thermal state does not affect the electrical behavior of the block. The thermal port is hidden by default. To enable the thermal port, select a thermal block variant.

The figure shows an idealized representation of the output voltage, *V _{out}*,
and the output current,

When the semiconductor turns on during the *n*th
switching cycle, the amount of thermal energy that the device dissipates
increments by a discrete amount. If you select ```
Voltage,
current, and temperature
```

for the **Thermal loss
dependent on** parameter, the equation for the incremental
change is

$${E}_{on(n)}=\frac{{V}_{off(n)}}{{V}_{off\_data}}fcn(T,{I}_{on(n-1)}),$$

*E*is the switch-on loss at the_{on(n)}*n*th switch-on event.*V*is the off-state output voltage,_{off(n)}*V*, just before the device switches on during the_{out}*n*th switching cycle.*V*is the_{off_data}**Off-state voltage for losses data**parameter value.*T*is the device temperature.*I*is the on-state output current,_{on(n-1)}*I*, just before the device switches off during the cycle that precedes the n_{out}*th*switching cycle.

The function *fcn* is a 2-D lookup table with
linear interpolation and linear extrapolation:

$$E=tablelookup({T}_{j\_data},{I}_{out\_data},{E}_{on\_data},T,{I}_{on(n-1)}),$$

*T*is the_{j_data}**Temperature vector, Tj**parameter value.*I*is the_{out_data}**Output current vector, Iout**parameter value.*E*is the_{on_data}**Switch-on loss, Eon=fcn(Tj,Iout)**parameter value.

If you select `Voltage and current`

for
the **Thermal loss dependent on** parameter, when
the semiconductor turns on during the *n*th switching
cycle, the equation that the block uses to calculate the incremental
change in the discrete amount of thermal energy that the device dissipates
is

$${E}_{on(n)}=\left(\frac{{V}_{off(n)}}{{V}_{off\_data}}\right)\left(\frac{{I}_{on(n-1)}}{{I}_{out\_scalar}}\right)({E}_{on\_scalar})$$

*I*is the_{out_scalar}**Output current, Iout**parameter value.*E*is the_{on_scalar}**Switch-on loss**parameter value.

When the semiconductor turns off during the *n*th
switching cycle, the amount of thermal energy that the device dissipates
increments by a discrete amount. If you select ```
Voltage,
current, and temperature
```

for the **Thermal loss
dependent on** parameter, the equation for the incremental
change is

$${E}_{off(n)}=\frac{{V}_{off(n)}}{{V}_{off\_data}}fcn(T,{I}_{on(n)}),$$

*E*is the switch-off loss at the_{off(n)}*n*th switch-off event.*V*is the off-state output voltage,_{off(n)}*V*, just before the device switches on during the_{out}*n*th switching cycle.*V*is the_{off_data}**Off-state voltage for losses data**parameter value.*T*is the device temperature.*I*is the on-state output current,_{on(n)}*I*, just before the device switches off during the_{out}*n*th switching cycle.

The function *fcn* is a 2-D lookup table with
linear interpolation and linear extrapolation:

$$E=tablelookup({T}_{j\_data},{I}_{out\_data},{E}_{off\_data},T,{I}_{on(n)}),$$

*T*is the_{j_data}**Temperature vector, Tj**parameter value.*I*is the_{out_data}**Output current vector, Iout**parameter value.*E*is the_{off_data}**Switch-off loss, Eoff=fcn(Tj,Iout)**parameter value.

If you select `Voltage and current`

for
the **Thermal loss dependent on** parameter, when
the semiconductor turns off during the *n*th switching
cycle, the equation that the block uses to calculate the incremental
change in the discrete amount of thermal energy that the device dissipates
is

$${E}_{off(n)}=\left(\frac{{V}_{off(n)}}{{V}_{off\_data}}\right)\left(\frac{{I}_{on(n-1)}}{{I}_{out\_scalar}}\right)({E}_{off\_scalar})$$

*I*is the_{out_scalar}**Output current, Iout**parameter value.*E*is the_{off_scalar}**Switch-off loss**parameter value.

If you select `Voltage, current, and temperature`

for
the **Thermal loss dependent on** parameter, then,
for both the on state and the off state, the heat loss due to electrical
conduction is

$${E}_{conduction}={\displaystyle \int fcn}(T,{I}_{out})\text{\hspace{0.17em}}dt,$$

*E*is the heat loss due to electrical conduction._{conduction}*T*is the device temperature.*I*is the device output current._{out}

The function *fcn* is a 2-D lookup table:

$${Q}_{conduction}=tablelookup({T}_{j\_data},{I}_{out\_data},{I}_{out\_data\_repmat}\text{\hspace{0.17em}}.*\text{\hspace{0.17em}}{V}_{on\_data},T,{I}_{out}),$$

*T*is the_{j_data}**Temperature vector, Tj**parameter value.*I*is the_{out_data}**Output current vector, Iout**parameter value.*I*is a matrix that contains length,_{out_data_repmat}*T*, copies of_{j_data}*I*._{out_data}*V*is the_{on_data}**On-state voltage, Von=fcn(Tj,Iout)**parameter value.

If you select `Voltage and current`

for
the **Thermal loss dependent on** parameter, then,
for both the on state and the off state, the heat loss due to electrical
conduction is

$${E}_{conduction}={\displaystyle \int \left({I}_{out}*{V}_{on\_scalar}\right)dt},$$

The block uses the **Energy dissipation time constant** parameter
to filter the amount of heat flow that the block outputs. The filtering
allows the block to:

Avoid discrete increments for the heat flow output

Handle a variable switching frequency

The filtered heat flow is

$$Q=\frac{1}{\tau}\left({\displaystyle \sum _{i=1}^{n}{E}_{on(i)}}+{\displaystyle \sum _{i=1}^{n}{E}_{off(i)}}+{E}_{conduction}-{\displaystyle \int Q\text{\hspace{0.17em}}dt}\right),$$

*Q*is the heat flow from the component.*τ*is the**Energy dissipation time constant**parameter value.*n*is the number of switching cycles.*E*is the switch-on loss at the_{on(i)}*i*th switch-on event.*E*is the switch-off loss at the_{off(i)}*i*th switch-off event.*E*is the heat loss due to electrical conduction._{conduction}*∫Qdt*is the total heat previously dissipated from the component.

The figure shows the block port names.

`G`

Port associated with the gate terminal. You can set the port to either a physical signal or electrical port.

`A`

Electrical conserving port associated with the anode terminal.

`K`

Electrical conserving port associated with the cathode terminal.

`H`

Thermal conserving port. The thermal port is optional and is hidden by default. To enable this port, select a variant that includes a thermal port.

**Forward voltage, Vf**Forward voltage at which the device turns on. The default value is

`0.8`

`V`

.**On-state resistance**Anode-cathode resistance when the device is on. The default value is

`0.001`

`Ohm`

.**Off-state conductance**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**. The default value is`1e-5`

`1/Ohm`

.**Gate trigger voltage, Vgt**Gate-cathode voltage threshold. The device turns on when the gate-cathode voltage is above this value. The default value is

`6`

`V`

.**Holding current**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. The default value is

`1`

`A`

.

**Integral protection diode**Block integral protection diode. The default value is

`None`

.The diodes you can select are:

`Protection diode with no dynamics`

`Protection diode with charge dynamics`

When you select `Protection diode with no dynamics`

,
additional parameters appear.

When you select `Protection diode with charge dynamics`

,
additional parameters appear.

Additional Parameters for Protection diode with charge dynamics

The **Thermal Model** tab is enabled only when
you select a block variant that includes a thermal port.

**Thermal loss dependent on**Select a parameterization method. The option that you select determines which other parameters are enabled. Options are:

`Voltage and current`

— Use scalar values to specify the output current, switch-on loss, switch-off loss, and on-state voltage data.`Voltage, current, and temperature`

— Use vectors to specify the output current, switch-on loss, switch-off loss, on-state voltage, and temperature data. This is the default parameterization method.

**Off-state voltage for losses data**The output voltage of the device during the off state. This is the blocking voltage at which the switch-on loss and switch-off loss data are defined. The default value is

`300`

`V`

.**Energy dissipation time constant**Time constant used to average the switch-on losses, switch-off losses, and conduction losses. This value is equal to the period of the minimum switching frequency. The default value is

`1e-4`

`s`

.

Additional Parameters for Parameterizing by Voltage, Current, and Temperature

Additional Parameters for Parameterizing by Voltage and Current

Commutation Diode | Diode | GTO | IGBT | Ideal Semiconductor Switch | MOSFET

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