IGBT (Ideal, Switching)
The ideal insulated gate bipolar transistor for switching circuits.
Description
The IGBT (Ideal, Switching) block models the ideal Insulated-gate bipolar transistor (IGBT) for switching circuits. The switching characteristic of an IGBT is such that if the gate-emitter voltage exceeds a given threshold voltage , the IGBT is in the open state. Otherwise, the device is in the closed state. This figure shows a typical volt-ampere characteristic:
In the open state, the collector-emitter channel behaves like a linear diode with a forward voltage drop and resistance .
In the closed state, the collector-emitter channel behaves like a linear resistor with low conductance .
The defining equations can be written as
if and ,
otherwise ,
where
-
- collector-emitter voltage
-
- forward voltage;
-
- gate-emitter voltage;
-
- threshold voltage;
-
- collector-emitter current;
-
- open state resistance;
-
- closed state conductivity.
Integrated protection diode option
Using the Integral Diode parameters, an internal diode can be connected between the emitter and collector. The integrated diode protects the device by providing a conduction channel for reverse current that can occur when the voltage to an inductive load is abruptly cut off.
Set the value of Integral protection diode depending on the purpose.
| Purpose | Value to select | Integral protection diode | |
|---|---|---|---|
Do not enable protection. |
|
Not used |
|
Enable protection. |
Simulation speed priority. |
|
Adds internal unit Diode (Advanced). |
Priority of modelling accuracy - accurate indication of charge dynamics in reverse mode. |
|
Adds internal block Diode (Advanced) with charge dynamics. |
|
Ports
Parameters
Main
Gate-control port - option for specifying the type of gate-control port
Signal control port (by default) | Electrical control port
Option to specify the physical or electrical gate control port of the transistor.
Forward voltage, Vf - forward voltage
0.8 V (by default)
Minimum collector and emitter voltages required for the angle of slope of the transistor’s volt-ampere characteristic to be equal to , where is the value of the On-state resistance parameter.
On-state resistance is the resistance in the open state
`0.01 ohm (by default)
Resistance of the open collector-emitter channel.
Off-state conductance - closed state conductance
1e-6 1/ohm (by default)
Collector-emitter closed state conductance. The value of this parameter must be less than , where is the value of On-state resistance.
Threshold voltage, Vth - threshold voltage
2 V (by default)
Threshold gate-emitter voltage. The device is switched on when the gate-emitter voltage exceeds this value.
Integral Diode
Integral protection diode - internal protection diode (suppressor)
None (by default) | Diode with no dynamics | Diode with charge dynamics
Specify whether the unit includes a protection diode (suppressor). By default, `None' is used.
If the internal protection diode is to be enabled, two options are available:
-
Diode with no dynamics. -
`Diode with charge dynamics
Forward voltage - forward voltage
0.8 V (by default)
Minimum voltage required at the negative and positive ports of the block to make the gradient of the diode’s volt-ampere characteristic equal to 1/ , where is the value of the On resistance parameter.
Dependencies
To use this parameter, set the Integral protection diode parameter to Diode with no dynamics or Diode with charge dynamics.
On resistance - resistance when directly connected
0.001 ohms (by default).
The diode resistance in the open state when the voltage is higher than the value set by the Forward voltage parameter.
Dependencies
To use this parameter, set Integral protection diode to Diode with no dynamics or Diode with charge dynamics.
Off conductance - closed state conductance
1e-5 1/ohm (by default).
The conductance of the diode when switched back on.
Dependencies
To use this parameter, set Integral protection diode to Diode with no dynamics or Diode with charge dynamics.
Junction capacitance - junction capacitance
5e-8 F (By default).
The value of the capacitance inherent in the depletion zone transition, acting as a dielectric and separating the anode and cathode junctions.
Dependencies
To use this parameter, set Integral protection diode to `Diode with charge dynamics'.
Peak reverse current, iRM - peak reverse current
-235 A (By default).
Peak reverse current measured by an external test circuit. This value must be less than zero. The value by default is -235 A.
Dependencies
To use this parameter, set Integral protection diode to `Diode with charge dynamics'.
Initial forward current when measuring iRM - Initial forward current when measuring iRM
300 A (By default).
Initial forward current (at initial switch-on time) when measuring peak reverse current. This value must be greater than zero.
Dependencies
To use this parameter, set Integral protection diode to `Diode with charge dynamics'.
Rate of change of current when measuring iRM - rate of change of current when measuring iRM
-50 A/µs (By default).
Rate of change of current when measuring peak reverse current. This value must be less than zero.
Dependencies
To use this parameter, set Integral protection diode to `Diode with charge dynamics'.
Reverse recovery time parametrization - type of reverse recovery time definition
| Specify stretch factor (by default) | Specify reverse recovery time directly ` | `Specify reverse recovery charge.
Selecting Specify stretch factor or Specify reverse recovery charge specifies the value used by the unit to calculate the reverse recovery time.
Dependencies
To use this option, set Integral protection diode to `Diode with charge dynamics'.
Reverse recovery time, trr - reverse recovery time
`15 µs (By default)
The amount of time it takes for a diode to switch off when its voltage reverses polarity from forward bias to reverse bias.
The interval between when the current initially crosses zero (when the diode switches off) and when the current drops to less than 10% of the peak current. The value of Reverse recovery time, trr must be greater than the value of Peak reverse current, iRM divided by the value of Rate of change of current when measuring, iRM.
Dependencies
To use this parameter, set the Integral protection diode parameter to `Diode with charge dynamics' and the Reverse recovery time parametrization parameter to `Specify reverse recovery time directly'.
Reverse recovery time stretch factor - reverse recovery time stretch factor
3 (By default).
The value that the block uses to calculate Reverse recovery time, trr. This value must be greater than 1. Specifying the stretch factor is a simpler way of parameterising the reverse recovery time than specifying the reverse recovery charge. The larger the value of the stretch factor, the longer the time required for the reverse recovery current to dissipate.
Dependencies
To use this parameter, set the Integral protection diode parameter to `Diode with charge dynamics' and the Reverse recovery time parametrization parameter to `Specify stretch factor'.
Reverse recovery charge, Qrr - reverse recovery charge
1500 µAs (by default).
The value the unit uses to calculate Reverse recovery time, trrr. Use this parameter if the unit parameters specify the reverse recovery charge value instead of the reverse recovery time value as the type of reverse recovery time definition.
The reverse recovery charge is the total charge that continues to dissipate after the diode is switched off. The value must be less than , where:
-
- value specified for the Peak reverse current, iRM parameter;
-
- the value specified for the parameter Rate of change of current when measuring iRM.
Dependencies
To use this parameter, set the Integral protection diode parameter to `Diode with charge dynamics' and the Reverse recovery time parametrization parameter to `Specify reverse recovery charge'.