Thyristor (Piecewise Linear)

Thyristor

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Libraries:
Simscape / Electrical / Semiconductors & Converters

Description

The Thyristor (Piecewise Linear) 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.

To define the I-V characteristic of the thyristor, set the On-state behavior and switching losses parameter to either Specify constant values or Tabulate. The Tabulate option is available only if you expose the thermal port of the block.

In the on state, the anode-cathode path behaves like a linear diode with forward-voltage drop, V_f, and on-resistance, R_on. However, if you expose the thermal port of the block and parameterize the device using tabulated I-V data, the tabulated resistance is a function of the temperature and current.

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.	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.	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.

Model Gate Port and Thermal Effects

You can choose between physical or electrical ports to control the gate terminal and expose the thermal port to model the heat that switching events and conduction losses generate. To choose the gate-control port, set the Gate-control port parameter to PS or Electrical. To expose the thermal port, set the Modeling option parameter to No thermal port or Show thermal port.

For more information about using thermal ports, see Simulating Thermal Effects in Semiconductors.

Thermal Losses

Switching losses are major sources of thermal loss in semiconductors. During each on-off switching transition, the thyristor parasitics store and then dissipate energy.

Switching losses depend on the off-state voltage and the on-state current. When a switching device turns on, the power losses depend on the initial off-state voltage across the device and the final on-state current when the device is in its fully on state.

This block applies switching losses by stepping up the junction temperature with a value equal to the switching loss divided by the total thermal mass at the junction. You must specify the energy dissipated during a single switch-on event. You must also specify the corresponding values of the off-state voltage and on-state current at which you quote the losses. You can parameterize the switch-on loss, depending on the data you have. Use tabulated data if they are available.

• To specify a scalar value for the switch-on loss, set the On-state behavior and switching losses parameter to Specify constant values. The Switch-on loss parameter value sets the sizes of the switch-on loss. The block scales the loss by the off-state voltage and the on-state current.

• To specify the switch-on loss as a function of the junction temperature and on-state current, set the On-state behavior and switching losses parameter to Tabulate. The Switch-on loss, Eon(Tj,Iak) parameter sets the size of the loss. The block scales the loss by the off-state voltage.

When the current falls below the Holding current parameter value, the device switches off. The Natural commutation rectification loss parameter value defines the switch-off loss. The block does not scale this loss by the off-state voltage or on-state current because it is not possible to know when to measure the starting current or final voltage for the rectification loss.

Reverse recovery loss can be a significant source of thermal loss in diodes. The diode dissipates energy every time it turns off, from its conducting state to the open-circuit state. To model reverse recovery loss:

• Set Modeling option to Show thermal port.

• Set Integral protection diode to Diode with no dynamics.

If you set the Reverse recovery loss model parameter to Tabulated loss, the value of the Reverse recovery loss table, Erec(Tj, If) parameter specifies the dissipated energy as a function of the junction temperature and the forward current just before the switching event. The off-state voltage linearly scales the losses relative to the Turn-off voltage when measuring recovery loss, Vrec parameter value. The table uses delayed values for the current and voltage. To use a value in the lookup table that is close to the instantaneous value, set the Filter time constant for voltage and current values parameter to a value that is lower than the fastest switching period.

If you set the Reverse recovery loss model parameter to Fixed loss, the value of the Reverse recovery loss parameter specifies the energy dissipated during each turn-off event. If you select the Scale reverse recovery loss with current and voltage parameter, then the block scales this loss value linearly by the on-state current and the off-state voltage. To use scaling values that are close to the instantaneous values, set Filter time constant for voltage and current values to a value that is lower than the fastest switching period.

As an alternative method to model reverse recovery, you can set the Integral protection diode parameter to Diode with charge dynamics. However, this approach requires smaller simulation time steps than using the first approach.

Note

The block does not know the current after a switching event during the simulation, so the block records the on-state current once the current is greater than the holding current for a time longer than the value specified by the Wait time before switch-on current measurement parameter. Similarly, the block records the off-state voltage at the point that the devices switches on. For this reason, the logged simulation data does not report the switching losses to the thermal network until one switching cycle later. To learn how to log and plot simulation data, see the Log and Plot Simulation Data example.

For all ideal switching devices, the logged simulation data reports the thermal losses as lastTurnOffLoss, lastTurnOnLoss, and lastReverseRecoveryLoss. For the Thyristor (Piecewise Linear) block, the lastTurnOnLoss is equal to the Natural commutation rectification loss parameter value. These variables include losses as a pulse with an amplitude equal to the energy loss. If you use a script to sum the total losses over a defined simulation period, you must sum the pulse values at each pulse rising edge. Alternatively, you can extract conduction and switching losses from logged data using the ee_getPowerLossSummary and ee_getPowerLossTimeSeries functions.

You can also access the total accumulated switching losses from the accumulatedSwitchingLosses variable in the logged simulation data. This variable sums all switching losses to date, including reverse recovery losses for the diode.

The power_dissipated variable in the logged simulation data does not include switching losses because the block models these losses as instantaneous events. The power_dissipated variable reports ohmic on-state losses.

If you use tabulated data to model the switching losses or reverse recovery losses, check that the temperature and current are in the range you specify. If you do not define a realistic thermal model, for example, if the junction mass or the conductance from the junction to the case is too small, the temperature can exceed the range you specify, causing the block to extrapolate the losses to nonphysical values.

Variables

To set the priority and initial target values for the block variables before simulation, use the Initial Targets section in the block dialog box or Property Inspector. For more information, see Set Priority and Initial Target for Block Variables.

Use nominal values to specify the expected magnitude of a variable in a model. Using system scaling based on nominal values increases the simulation robustness. Nominal values can come from different sources. One of these sources is the Nominal Values section in the block dialog box or Property Inspector. For more information, see System Scaling by Nominal Values.

Ports

The figure shows the block port names.

Conserving

G — Gate terminal

electrical

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

A — Anode terminal

electrical

Electrical conserving port associated with the anode terminal.

K — Cathode terminal

electrical

Electrical conserving port associated with the cathode terminal.

H — Thermal port

thermal

Thermal conserving port.

Dependencies

To enable this port, set Modeling option to Show thermal port.

Parameters

Modeling option — Thermal port visibility

No thermal port (default) | Show thermal port

Whether to enable the thermal port.

Main

This table shows how the visibility of Main parameters depends on how you configure the Modeling option and On-state behavior and switching losses parameters. To learn how to read this table, see Parameter Dependencies.

Main Parameter Dependencies

Parameters and Options
Modeling option
No thermal port				Show thermal port
Gate-control port				Gate-control port
Forward voltage, Vf				Gate trigger voltage, Vgt
On-state resistance				Holding current
Off-state conductance				On-state behavior and switching losses
				Specify constant values	Tabulate
Gate trigger voltage, Vgt				Forward voltage, Vf	On-state voltage, Vak(Tj,Iak)
Holding current				On-state resistance	Temperature vector, Tj
				Off-state conductance	Anode-cathode current vector, Iak
					Off-state conductance

Gate-control port — Whether to specify physical or electrical control port

PS (default) | Electrical

Whether to specify physical or electrical control port for the switch gate.

On-state behavior and switching losses — On-state current for switching loss data

Specify constant values (default) | Tabulate

Parameterization method for on-state behavior and switching losses, specified as one of these values:

• Specify constant values — Use scalar values to specify the output current, switch-on loss, and switch-off loss data.

• Tabulate — Use vectors to specify the output current and temperature data. Use matrices to specify the switch-on loss and switch-off loss data.

Forward voltage, Vf — Forward voltage

0.8 V (default)

Forward voltage at which the device turns on.

Dependencies

See the Main Parameter Dependencies table.

On-state resistance — On-state resistance

0.001 Ohm (default)

Anode-cathode resistance when the device is on.

Dependencies

See the Main Parameter Dependencies table.

Off-state conductance — Off-state conductance

1e-5 1/Ohm (default)

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.

Dependencies

See the Main Parameter Dependencies table.

Gate trigger voltage, Vgt — Gate trigger voltage

6 V (default)

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

Dependencies

See the Main Parameter Dependencies table.

Holding current — Holding current

1 A (default)

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.

Dependencies

See the Main Parameter Dependencies table.

On-state voltage, Vak(Tj,Iak) — On-state voltage

[0, .1, .6, .8, 1, 1.3, 1.6, 2, 2.4; 0, .1, .7, 1, 1.2, 1.5, 1.9, 2.4, 2.8] V (default) | matrix of nonnegative scalars

Voltage drop across the device in a triggered conductive state. This parameter is a function of temperature and final on-state output current.

Dependencies

See the Main Parameter Dependencies table.

Temperature vector, Tj — Temperature values

[298.15, 398.15] K (default) | vector

Temperature values at which you quote the on-state voltage.

Dependencies

See the Main Parameter Dependencies table.

Anode-cathode current vector, Iak — Anode-cathode current vector

[0, .1, 1, 5, 10, 20, 40, 70, 100] A (default)

Anode-cathode currents for which the on-state voltage is defined. The first element must be zero. Specify this parameter using a vector quantity.

Dependencies

See the Main Parameter Dependencies table.

Switching Losses

To enable these parameters, set Modeling option to Show thermal port.

Switch-on loss — Switch-on loss

22.86e-3 J (default) | positive scalar

Energy dissipated during a single switch-on event.

Dependencies

To enable this parameter, set On-state behavior and switching losses to Specify constant values.

Natural commutation rectification loss — Natural commutation rectification loss

10e-3 J (default) | positive scalar

Rectification loss applied at the point that the block switches off when the current falls below the Holding current. Specify this parameter using a scalar quantity.

Off-state voltage for switching loss data — Off-state voltage for losses data

300 V (default) | positive scalar

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.

On-state current for switching loss data — Output current

600 A (default) | positive scalar

Output currents for which the switch-on loss, switch-off loss, and on-state voltage are defined. The first element must be zero. Specify this parameter using a scalar quantity.

Note

This parameter is measured at the point that the gate voltage falls below the Gate trigger voltage, Vgt. The turn-on pulse is longer than the time it takes the current to reach its maximum value.

Dependencies

To enable this parameter, set On-state behavior and switching losses to Specify constant values.

Switch-on loss, Eon(Tj,Iak) — Switch-on loss

[0, .0024, .024, .12, .2, .48, 1.04, 2.16, 3.24; 0, .003, .03, .15, .25, .6, 1.3, 2.7, 4.05] * 1e-3 J (default) | matrix of nonnegative scalars

Energy dissipated during a single switch-on event as a function of temperature and final on-state output current.

Dependencies

To enable this parameter, set On-state behavior and switching losses to Tabulate.

Temperature vector for switching losses, Tj — Temperature for switching losses

[298.15, 398.15] K (default) | vector

Temperature values at which you quote the switch-on loss and switch-off loss.

Dependencies

To enable this parameter, set On-state behavior and switching losses to Tabulate.

Anode-cathode current vector for switching losses, Iak — Anode-cathode current vector for switching losses

[0, .1, 1, 5, 10, 20, 40, 70, 100] A (default) | vector of nonnegative scalars

Anode-cathode currents at which you quote the switch-on loss and switch-off-loss. The first element must be zero.

Dependencies

To enable this parameter, set On-state behavior and switching losses to Tabulate.

Wait time before switch-on current measurement — Time before on-state current is measured

1e-4 s (default) | nonnegative scalar

Time to wait before recording the on-state current.

Integral Diode

Integral protection diode — Integral protection diode

External diode (default) | Protection diode with no dynamics | Protection diode with charge dynamics

Block integral protection diode.

The diodes you can select are:

• Protection diode with no dynamics

• Protection diode with charge dynamics

Diode model — Diode model

Piecewise Linear (default) | Tabulated I-V curve

Select one of these diode models:

• Piecewise Linear — Use a piecewise linear model for the diode, as described in Piecewise Linear Diode. This is the default method.

• Tabulated I-V curve — Use tabulated forward bias I-V data plus fixed reverse bias off conductance.

Dependencies

This parameter is visible only when the thermal port is exposed and the Integral protection diode parameter is set to Protection diode with no dynamics or Protection diode with charge dynamics.

Table type — Tabulated function

Table in If(Tj,Vf) form (default) | Table in Vf(Tj,If) form

Whether to tabulate the current as a function of temperature and voltage or the voltage as a function of temperature and current.

Dependencies

This parameter is visible only when the thermal port is exposed and the Integral protection diode parameter is set to Protection diode with no dynamics or Protection diode with charge dynamics and Diode model is set to Tabulated I-V curve.

Forward voltage — Forward voltage

0.8 V (default)

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

Dependencies

To enable this parameter:

• If the thermal port is hidden, set Integral protection diode to Diode with no dynamics or Diode with charge dynamics.

• If the thermal port is exposed, set Integral protection diode to Diode with no dynamics or Diode with charge dynamics and Diode model to Piecewise linear.

On resistance — On resistance

0.001 Ohm (default)

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

Dependencies

To enable this parameter:

• If the thermal port is hidden, set Integral protection diode to Diode with no dynamics or Diode with charge dynamics.

• If the thermal port is exposed, set Integral protection diode to Diode with no dynamics or Diode with charge dynamics and Diode model to Piecewise linear.

Forward currents, If(Tj,Vf) — Vector of forward currents

[.07, .12, .19, 1.75, 4.24, 7.32, 11.2; .16, .3, .72, 2.14, 4.02, 6.35, 9.12] A (default) | nonnegative vector

Forward currents. This parameter must be a vector of at least three nonnegative elements.

Dependencies

To enable this parameter, expose the thermal port and set Diode model to Tabulated I-V curve and Table type to Table in If(Tj,Vf) form.

Junction temperatures, Tj — Vector of junction temperatures

[25, 125] degC (default)

Vector of junction temperatures. This parameter must be a vector of at least two elements.

Dependencies

To enable this parameter, expose the thermal port and set Diode model to Tabulated I-V curve.

Forward voltages, Vf — Vector of forward voltages

[.5, .7, .9, 1.3, 1.7, 2.1, 2.5] V (default)

Vector of forward voltages. This parameter must be a vector of at least three nonnegative values.

Dependencies

To enable this parameter, expose the thermal port and set Diode model to Tabulated I-V curve and Table type to Table in If(Tj,Vf) form.

Forward voltages, Vf(Tj,If) — Vector of forward voltages

[.9, 1.15, 1.25, 1.5, 1.75, 2.17, 2.6, 2.85; .58, .68, .75, 1.1, 1.38, 1.77, 2.27, 2.7] V (default) | nonnegative vector

Forward voltages. This parameter must be a vector of at least three nonnegative elements.

Dependencies

To enable this parameter, expose the thermal port and set Diode model to Tabulated I-V curve and Table type to Table in Vf(Tj,If) form.

Forward currents, If — Vector of forward currents

[.1, .2, .5, 1, 2, 4, 7, 10] A (default)

Vector of forward currents. This parameter must be a vector of at least three nonnegative values.

Dependencies

To enable this parameter, expose the thermal port and set Diode model to Tabulated I-V curve and Table type to Table in Vf(Tj,If) form.

Off conductance — Off conductance

1e-5 1/Ohm (default)

Conductance of the reverse-biased diode.

Dependencies

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

Reverse recovery loss model — Model for reverse recovery loss

Fixed loss (default) | Tabulated loss

Since R2023a

Whether to model fixed or tabulated reverse recovery losses.

Dependencies

To enable this parameter, set the Modeling option parameter to Show thermal port and set the Integral protection diode parameter to Diode with no dynamics.

Reverse recovery loss — Reverse recovery loss

0 J (default) | nonnegative scalar

Since R2023a

Dissipated energy in each turn-off event, regardless of the state of the diode before or after the switching event.

Dependencies

To enable this parameter, set the Reverse recovery loss model parameter to Fixed loss.

Scale reverse recovery loss with current and voltage — Option to scale reverse recovery loss

On (default) | Off

Since R2023b

Option to scale reverse recovery loss with current and voltage.

Dependencies

To enable this parameter:

• Set Modeling option to Show thermal port.

• Set Integral protection diode to Diode with no dynamics.

• Set Reverse recovery loss model to Fixed loss.

Reverse recovery loss table, Erect(Tj), If — Reverse recovery loss

zeros(2,3) J (default) | vector of nonnegative scalars

Since R2023a

Dissipated energy as a function of the forward current If just before the switching event, and final off-state voltage once the diode is in off state.

Dependencies

To enable this parameter, set the Reverse recovery loss model parameter to Tabulated loss.

Temperature vector for recovery loss table, Tj — Temperature vector for recovery loss table

[298.15 398.15] K (default) | vector

Since R2023a

Temperature vector used to tabulate reverse recovery loss.

Dependencies

To enable this parameter, set the Reverse recovery loss model parameter to Tabulated loss.

Forward current vector for recovery loss table, If — Forward current vector for recovery loss table

[.1, 1, 10] K (default) | vector of nonnegative scalars

Since R2023a

Forward current vector used to tabulate reverse recovery loss.

Dependencies

To enable this parameter, set the Reverse recovery loss model parameter to Tabulated loss.

Forward current when measuring recovery loss, Irec — Forward current when the block measures recovery loss

10 A (default) | positive scalar

Since R2023b

Forward current through the diode before the reverse recovery event that the block uses to measure recovery loss.

Dependencies

To enable this parameter, set Reverse recovery loss model to Fixed loss and select the Scale reverse recovery loss with current and voltage parameter.

Turn-off voltage when measuring recovery loss, Vrec — Turn-off voltage when measuring recovery loss

10 V (default) | positive scalar

Since R2023a

Voltage across the diode after the reverse recovery event used to measure recovery loss.

Dependencies

To enable this parameter, choose from one of these options:

• Set Reverse recovery loss model to Fixed loss and select the Scale reverse recovery loss with current and voltage parameter.

• Set the Reverse recovery loss model parameter to Tabulated loss.

Filter time constant for voltage and current values — Filter time constant for voltage and current values

1 / 1000 / 100 s (default) | positive scalar

Since R2023a

Filter time constant for voltage and current values used to calculate reverse recovery loss. Set this parameter to a value that is lower than the fastest switching period.

Dependencies

To enable this parameter, choose from one of these options:

• Set Reverse recovery loss model to Fixed loss and select the Scale reverse recovery loss with current and voltage parameter.

• Set the Reverse recovery loss model parameter to Tabulated loss.

Junction capacitance — Junction capacitance

50e-9 F (default)

Diode junction capacitance.

Dependencies

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

Peak reverse current, iRM — Peak reverse current

-235 A (default) | negative scalar

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 Diode with charge dynamics.

Initial forward current when measuring iRM — Initial forward current when measuring iRM

300 A (default) | positive scalar

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 Diode with charge dynamics.

Rate of change of current when measuring iRM — Rate of change of current when measuring iRM

-50A/μs (default) | negative scalar

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 Diode with charge dynamics.

Reverse recovery time parameterization — Reverse recovery time parameterization

Specify reverse recovery time directly (default) | Specify stretch factor | Specify reverse recovery charge

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 Diode with charge dynamics.

Reverse recovery time, trr — Reverse recovery time

15 μs (default)

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 Diode with charge dynamics and the Reverse recovery time parameterization parameter is set to Specify reverse recovery time directly.

Reverse recovery time stretch factor — Reverse recovery time stretch factor

3 (default)

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 Diode with charge dynamics and the Reverse recovery time parameterization parameter is set to Specify stretch factor.

Reverse recovery charge, Qrr — Reverse recovery charge

1500 μAs (default)

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:

• i_RM 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 Diode with charge dynamics and the Reverse recovery time parameterization parameter is set to Specify reverse recovery charge.

Diode turn-off voltage when measuring Erec — Diode turn-off voltage when measuring Erec

-600 V (default)

Voltage between the diode in steady-state.

Dependencies

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

Stray inductance when measuring Erec — Stray inductance when measuring Erec

150 nH (default)

Total unintended inductance in the measurement circuit. The block uses this value to calculate Reverse recovery energy, Erec.

Dependencies

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

Reverse recovery energy, Erec — Reverse recovery energy

0.03 J (default)

Total switching losses due to the diode reverse recovery.

Dependencies

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

For more information on these parameters, see Diode.

Thermal Port

To enable these parameters, set Modeling option to Show thermal port.

Thermal network — Options for thermal network modeling

External (default) | Specify junction and case thermal parameters | Cauer model | Cauer model parameterized with Foster coefficients

Options for modeling the thermal network of the block.

Thermal mass parameterization — Option to parameterize thermal mass

By thermal time constants (default) | By thermal mass

Options to parameterize the thermal mass:

• By thermal time constants — Parameterize the thermal masses in terms of thermal time constants.

• By thermal mass — Specify the thermal mass values directly.

Dependencies

To enable this parameter, set Thermal network to Specify junction and case thermal parameters, Cauer model, or Cauer model parameterized with Foster coefficients.

Junction case and case-ambient (or case-heatsink) thermal resistances, [R_JC R_CA] — Junction case and case-ambient (or case-heatsink) thermal resistances

[.08, .5] K/W (default) | vector of positive values

Row vector [ R_JC R_CA ] of two thermal resistance values, represented by two Conductive Heat Transfer blocks. The first value, R_JC, is the thermal resistance between the junction and the case. The second value, R_CA, is the thermal resistance between port H and the device case.

Dependencies

To enable this parameter, set Thermal network to Specify junction and case thermal parameters.

Junction and case thermal time constants, [t_J t_C] — Junction and case thermal time constants

[.001, .2] s (default) | vector of positive values

Row vector [ t_J t_C ] of two thermal time constant values. The first value, t_J, is the junction time constant. The second value, t_C, is the case time constant.

Dependencies

To enable this parameter, set Thermal network to Specify junction and case thermal parameters and Thermal mass parameterization to By thermal time constants.

Junction and case thermal masses, [M_J M_C] — Junction and case thermal masses

[.01, .5] J/K (default) | vector of positive values

Row vector [ M_J M_C ] of two thermal mass values. The first value, M_J, is the junction thermal mass. The second value, M_C, is the case thermal mass.

Dependencies

To enable this parameter, set Thermal network to Specify junction and case thermal parameters and Thermal mass parameterization to By thermal mass.

Junction and case initial temperatures, [T_J T_C] — Junction and case initial temperatures

[25, 25] degC (default) | vector of positive values

Row vector [ T_J T_C ] of two temperature values. The first value, T_J, is the junction initial temperature. The second value, T_C, is the case initial temperature.

Dependencies

To enable this parameter, set Thermal network to Specify junction and case thermal parameters.

Thermal resistances, [R1 R2 … Rn] — Thermal resistances

[.08,.1,.5] K/W (default) | [.08,.14,.22,.16] K/W | vector of positive values

Row vector of n thermal resistance values, represented by the Cauer elements used in the thermal network.

If you set Thermal network to Cauer model, the default value is [.08,.1,.5]. If you set Thermal network to Cauer model parameterized with Foster coefficients, the default value is [.08,.14,.22,.16].

Dependencies

To enable this parameter, set Thermal network to Cauer model or Cauer model parameterized with Foster coefficients.

Thermal masses, [M1 M2 … Mn] — Thermal masses

[.01,.1,.5] J/K (default) | [.001,.005,.05,.5] J/K | vector of positive values

Row vector of n thermal mass values, where n is the number of Cauer elements used in the thermal network.

If you set Thermal network to Cauer model, the default value is [.01,.1,.5]. If you set Thermal network to Cauer model parameterized with Foster coefficients, the default value is [.001,.005,.05,.5].

Dependencies

To enable this parameter, set Thermal network to Cauer model or Cauer model parameterized with Foster coefficients and Thermal mass parameterization to By thermal mass.

Thermal masses initial temperatures, [T1 T2 … Tn] — Thermal masses initial temperatures

[25, 25, 25] degC (default) | vector of positive values

Row vector of temperature values that corresponds to the temperature drop across each thermal capacity in the model.

Dependencies

To enable this parameter, set Thermal network to Cauer model.

Thermal time constants, [t1 t2 … tn] — Thermal time constants

[.001,.1,.2] s (default) | [7e-05, .0007, .01, .08] s | vector of positive values

Row vector of n thermal time constant values, where n is the number of Cauer elements used in the thermal network. The length of this vector must match the length of Thermal resistances, [R1 R2 … Rn]. With this parameterization, the thermal masses are computed as Mi = ti/Ri, where Mi, ti and Ri are the thermal mass, thermal time, and thermal resistance for the i^th Cauer element (if you set Thermal network to Cauer model) or Foster element (if you set Thermal network to Cauer model parameterized with Foster coefficients).

If you set Thermal network to Cauer model, the default value is [.001,.1,.2]. If you set Thermal network to Cauer model parameterized with Foster coefficients, the default value is [7e-05, .0007, .01, .08].

Dependencies

To enable this parameter, set Thermal network to Cauer model or Cauer model parameterized with Foster coefficientsand Thermal mass parameterization to By thermal time constants.

Initial node temperatures, [T1 T2 ... Tn] — Initial node temperatures

[25, 25, 25, 25] degC (default) | vector of positive values

Row vector of absolute temperature values of each node starting from the junction.

Dependencies

To enable this parameter, set Thermal network to Cauer model parameterized with Foster coefficients.

Junction thermal mass — Thermal mass of junction

0.01 J/K (default) | positive scalar

Thermal mass of the junction.

Dependencies

To enable this parameter, set Thermal network to External.

For more information about using thermal ports and the Thermal Port parameters, see Simulating Thermal Effects in Semiconductors.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

Version History

Introduced in R2013b

R2023b: Scale reverse recovery loss with current and voltage

You can now scale a fixed reverse recovery loss value with current and voltage. To enable this option, select the Scale reverse recovery loss with current and voltage parameter.

Models you create in R2023a or earlier default to no scaling for backwards compatibility.

R2023a: Update on integral diode modeling options

From R2023a forward, you can model reverse recovery loss in the Thyristor (Piecewise Linear) block. To enable the Reverse recovery loss model parameter, set the Modeling option parameter to Show thermal port and set the Integral protection diode to Diode with no dynamics.

R2021a: Removal of energy dissipation time constant parameter

From R2021a forward, the Energy dissipation time constant parameter of the Thyristor (Piecewise Linear) block is no longer used. A step in junction temperature now reflects the switching losses. If your model contains a thermal mass directly connected to this block thermal port, remove it and model the thermal mass inside the component itself.

R2020b: Update on switching losses and thermal modeling options

From R2020b forward, the Thyristor (Piecewise Linear) block has improved losses and thermal modeling options.

As a result of these changes:

• Electrical and thermal on-state losses are now always identical. The Thermal loss dependent on parameter and its options, Voltage and current and Voltage, current, and temperature, have been renamed to On-state behavior and switching losses, Specify constant values, and Tabulate:

  • If you selected Voltage and current for Thermal loss dependent on, then the electrical on-state losses are unchanged and their values are determined using the on-state resistance. However, the thermal on-state losses are now also determined by the on-state resistance. Prior to R2020b, the thermal on-state losses were defined by the product of the On-state voltage and Output current, Iout parameters.

  • If you selected Voltage, current, and temperature for Thermal loss dependent on, then the thermal on-state losses are unchanged and the On-state voltage, Vak(Tj,Iak) parameter sets their values. However, the electrical on-state losses are now equal to the thermal on-state losses. Prior to R2020b, the electrical on-state losses were defined by the value of the on-state resistance.

• The On-state voltage and the switch-off parameters are no longer used.