Thyristor (Piecewise Linear)
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
behaviour and switching losses parameter to either Specify
constant values
or Tabulate with temperature and
current
. The Tabulate with temperature and
current
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, Vf, and on-resistance,
Ron. 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, Goff.
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 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. 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. |
Modeling Variants
The block provides four modeling variants. To select the desired
variant, right-click the block in your model. From the context menu,
select > , and then one of these variants:
—
Contains a physical signal port that is associated with the gate terminal.
This variant is the default.
—
Contains an electrical conserving port that is associated with the
gate terminal.
—
Contains a thermal port and a physical signal port that is associated
with the gate terminal.
—
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. The thermal port is hidden by default. To enable the thermal
port, select a thermal block
variant.
Thermal Losses
Switching losses are one of the main sources of thermal loss in semiconductors.
During each on switching transition, the thyristor parasitics store and then
dissipate energy.
Switching losses depend on the off-state voltage and the on-state current. When
the switching device is turned on, the power losses depend on the initial off-state
voltage across the device and the final on-state current once the device is fully in
its on state. When the switching device is turned off, the power loss is defined by
the Natural commutation rectification loss parameter value.
This is the rectification loss applied at the point that the device switches off due
to the current falling below the holding current. This loss is a fixed value and it
is not scaled by the off-state voltage or the on-state current.
In this block, switching losses are applied to the attached thermal network using
a first-order time constant, resulting in smooth change in temperature of the
junction thermal mass. The Switch-on loss, Eon(Tj,Iak)
parameter value sets the sizes of the switching losses and they are either fixed or
dependent on junction temperature and drain-source current. In both cases, losses
are scaled by the off-state voltage prior to the latest device turn-on event.
Note
As the final current after a switching event is not known during the
simulation, the block records the on-state current at the point that the
gate-cathode voltage falls below the threshold voltage. Similarly, the block
records the off-state voltage at the point that the device is commanded on. For
this reason, the simlog does not report the switching losses to the thermal
network until one switching cycle later.
For all ideal switching devices, the switching losses are reported as
lastTurnOffLoss
and lastTurnOnLoss
(for the thyristor, this is the Natural commutation rectification
loss) and plotted as a pulse with 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 number of pulses scaled off the reported switching
loss.
Ports
The figure shows the block port names.
Conserving
expand all
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. The thermal port is optional and is hidden by
default. To enable this port, select a variant that includes a thermal
port.
Parameters
expand all
Main
This table shows how the visibility of Main parameters
depends on how you configure the Block choice and
On-state behavior and switching losses parameters. To learn
how to read this table, see Parameter Dependencies.
Main Parameter Dependencies
Parameters and
Options |
---|
Block choice |
PS
control port or
Electrical control
port | PS
control port | Thermal port or
Electrical control port | Thermal
port |
Forward voltage,
Vf | Gate trigger voltage,
Vgt |
On-state
resistance | Holding current |
Off-state
conductance | On-state behaviour and switching losses |
Specify constant
values | Tabulate with temperature and
current |
Gate trigger voltage,
Vgt | Forward voltage, Vf | On-state voltage,
Vak(Tj,Iak) |
Holding
current | On-state resistance | Off-state
conductance |
Off-state conductance | Switch-on loss,
Eon(Tj,Iak) |
Switch-on loss | Temperature vector,
Tj |
Natural commutation rectification loss | Anode-cathode current
vector, Iak |
Off-state voltage for switching loss data | Natural commutation
rectification loss |
On-state current for switching loss data | Off-state voltage for
switching loss data |
Energy dissipation time constant | Energy dissipation time
constant |
On-state behaviour and switching losses
— On-state current for switching loss data
Specify constant
values
(default) | Tabulate with temperature and
current
Select a parameterization method. The option that you select
determines which other parameters are enabled. Options are:
Specify constant values
— Use
scalar values to specify the output current, switch-on loss,
switch-off loss, and on-state voltage data. This is the
default parameterization method.
Tabulate with temperature and
current
— Use vectors to specify the
output current, switch-on loss, switch-off loss, and
temperature data.
Dependencies
See the Main Parameter Dependencies
table.
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.
Switch-on loss
— Switch-on loss
22.86e-3
J
(default)
Energy dissipated during a single switch-on event. This parameter is
defined as a function of temperature and final on-state output current.
Specify this parameter using a scalar quantity.
Dependencies
See the Main Parameter Dependencies
table.
Natural commutation rectification loss
— Natural commutation rectification loss
10e-3
J
(default)
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.
Dependencies
See the Main Parameter Dependencies
table.
Off-state voltage for switching loss data
— Off-state voltage for losses data
300
V
(default)
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.
Dependencies
See the Main Parameter Dependencies
table.
On-state current for switching loss data
— Output current
600
A
(default)
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
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)
Voltage drop across the device while it is in a triggered conductive
state. This parameter is defined as a function of temperature and final
on-state output current. Specify this parameter using a vector quantity.
Dependencies
See the Main Parameter Dependencies
table.
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)
Energy dissipated during a single switch on event. This parameter is
defined as a function of temperature and final on-state output current.
Specify this parameter using a vector quantity.
Dependencies
See the Main Parameter Dependencies
table.
Temperature vector, Tj
— Temperature vector
[298.15, 398.15]
K
(default)
Temperature values at which the switch-on loss, switch-off loss, and
on-state voltage are specified. Specify this parameter using a vector
quantity.
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 switch-on loss, switch-off- loss
and on-state voltage are defined. The first element must be zero.
Specify this parameter using a vector quantity.
Dependencies
See the Main Parameter Dependencies
table.
Energy dissipation time constant
— Time constant
1e-4
s
(default)
First-order time lag with which instantaneous switching losses
smoothly raise the junction temperature.
Dependencies
See the Main Parameter Dependencies
table.
Integral Diode
Integral protection diode
— Integral protection diode
None
(default) | Protection diode with no dynamics
| Protection diode with charge
dynamics
Block integral protection diode. The default value is
None
.
The diodes you can select are:
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
.
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/Ron, where Ron is the value of On resistance.
Dependencies
To enable this parameter:
If the thermal port is hidden, set Integral protection
diode to Protection diode with no
dynamics
or Protection diode with charge
dynamics
.
If the thermal port is exposed, set Integral protection
diode to Protection diode with no
dynamics
or Protection 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 Protection diode with no
dynamics
or Protection diode with charge
dynamics
.
If the thermal port is exposed, set Integral protection
diode to Protection diode with no
dynamics
or Protection 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
.
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
.
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 Protection diode with no dynamics
or Protection diode with charge dynamics
.
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 Protection 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 Protection 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 Protection diode with charge dynamics
.
Rate of change of current when measuring iRM
— Rate of change of current when measuring iRM
-50
A/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 Protection 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 Protection 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 Protection 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 Protection 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
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.
Thermal Port
Use the thermal port to simulate the effects of generated heat and device
temperature. For more information on using thermal ports and on the
Thermal Port parameters, see Simulating Thermal Effects in Semiconductors.
Compatibility Considerations
expand all
Update on switching losses and thermal modelling options
Behavior changed in R2020b
From R2020b forward, the Thyristor (Piecewise
Linear) block has improved losses and thermal modelling
options.
As a result of these changes:
The Energy dissipation time constant parameter 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.
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 with temperature and
current
:
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.
Extended Capabilities
C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.
Introduced in R2013b