Boost Converter
Controller-controlled step-up DC-DC voltage regulator.
Description
The Boost Converter unit is a converter that boosts the DC voltage under the control of a connected controller and gate signal generator. Boost converters are also known as boost voltage regulators because they increase the voltage magnitude.
The Boost Converter block allows you to model a non-synchronous converter with one switching device or a synchronous converter with two switching devices.
Switching device type options:
-
Ideal semiconductor switch. When G is between
0and1, the averaging switch is partially open. You can average the pulse width modulation (PWM) signal over a certain period. You can then downsample the model and use modulating waveforms instead of PWM signals.
Inverter topology
You can model the Boost Converter as a non-synchronous converter with a physical signal gate control port or two electrical control ports, or as a synchronous converter with a single electrical control port. To select the converter topology, set the Modelling option to:
-
Nonsynchronous converter- a non-synchronous converter with additional physical or electrical gate control ports. -
Synchronous converter- synchronous converter with multiplexed gate signals.
Non-synchronous step-up converter models contain an inductor, a power electronic key, a diode and an output capacitor.
The synchronous boost converter model contains an inductor, two power electronic switches and an output capacitor.
In each case the capacitor smooths the output voltage.
Protection
You can include integral protection diodes in your synchronous converter model. Integral diodes protect the semiconductor device by providing a conductive path for reverse current. An inductive load can create a high reverse voltage spike when the semiconductor device suddenly cuts off the voltage supply to the load.
To enable and configure the internal protection diodes, use the Diode parameters.
This table shows how to set the Model dynamics parameter depending on your purposes.
Purposes |
Select value |
Built-in protection diode |
|
Do not enable protection |
Not available |
Not available |
|
Enable protection |
Prioritise modelling speed |
|
Block Diod |
Prioritise model accuracy by accurately specifying charge dynamics in reverse mode |
|
Dynamic model of block Diod |
|
You can also include a snubber circuit for each switching device. Snubber circuits contain a resistor and a capacitor connected in series. They protect the switching devices from the high voltages that inductive loads create when the device disconnects the voltage supply to the load. In addition, the snubber circuits prevent the current from changing at an excessive rate when the switching device is switched on.
To enable and configure a snubber circuit for each switching device, use the Snubbers parameters.
Connecting signals to the gate control port
-
Non-synchronous converter model (
Nonsychronous converter) with the option of a directional control port (Signal control port):-
Create a directional control signal, e.g. from basic maths blocks, and connect it to the G port.
-
-
Non-synchronous converter model (
Nonsychronous converter) withElectrical control portoption:-
Connect the positive DC voltage signal to the G+ port.
-
Connect the negative DC voltage signal to the G- port.
-
-
Synchronous converter model (`Synchronous converter'):
-
Multiplex the converted gate control signals into a single vector using a dual-pulse gate multiplexer (see Two-Pulse Gate Multiplexer).
-
Connect the vector signal to the G port.
-
Ports
Input
G - gate contact (pin)
scalar
Control signal port associated with the switch gate.
Dependencies
To enable this port, set the Modelling option to Gate-control port and the Gate-control port to Signal.
Data types: Float64.
Non-directional
G - gate contact
electricity
Electrical port associated with the switch gate contact.
Dependencies
To enable this port, set the Modelling option to Synchronous converter.
Data types: Float64.
G+ - positive terminal of the switching device
scalar
Electrical port connected to the positive terminal of the switching device gate.
Dependencies
To enable this port, set the Modelling option to Nonsynchronous converter and the Gate-control port to Electrical.
Data types: Float64.
G- - negative terminal of the switching device
scalar
Electrical port connected to the negative terminal of the switching device gate.
Dependencies
To enable this port, set the Modelling option to Nonsynchronous converter and the Gate-control port to Electrical.
Data types: Float64.
1+ - positive DC voltage 1
scalar
Electrical port associated with positive DC voltage terminal 1.
Data types: Float64.
1- - negative DC voltage 1
scalar
An electrical port associated with the negative DC voltage terminal 1.
Data types: Float64.
2+ - positive DC voltage 2
scalar
An electrical port associated with the positive DC voltage terminal 2.
Data types: Float64.
2- - negative DC voltage 2
scalar
An electrical port associated with the negative DC voltage terminal 2.
Data types: Float64.
Parameters
Main
Modelling option - modelling of non-synchronous or synchronous converter
Nonsynchronous converter (by default) | Synchronous converter
Selects whether to model a non-synchronous or synchronous converter.
Switching devices
This table shows how the visibility of switching device parameters depends on the value of the Switching device parameter.
| *Switching device | Parameters and settings |
|---|---|
|
On-state resistance |
On-state resistance |
|
Off-state conductance |
Gate-control port - defines whether the control port is scalar or electrical.
Signal (by default) | Electrical
Scalar or electrical control port of the switch gate control.
Dependencies
To enable this port, set the Modelling option to Nonsynchronous converter.
Switching device - switch type
Ideal Semiconductor Switch (by default).
Switching device type for the inverter. For the synchronous model, the switches are identical.
On-state resistance - On-state resistance
0.001 Ohm (By default) | scalar
On-state resistance between anode and cathode.
For different types of switching devices, the resistance in the on state is assumed to be equal to:
-
For GTO, the rate of change of voltage versus current above the forward voltage.
-
For Ideal semiconductor switches, the anode-cathode resistance when the device is switched on.
-
For IGBT - collector-emitter resistance when the device is switched on.
-
For Thyristor - anode-cathode resistance when the device is switched on.
-
For Averaged switch - anode-cathode resistance when the device is switched on.
Off-state conductance - off-state conductance
Anode-to-cathode conductance in the off-state.
Conductivity when the device is switched off. The value must be less than 1/R, where R is the standby resistance value.
For different types of switching devices, the standby resistance is assumed to be equal to:
-
For GTO, the anode-to-cathode conductivity.
-
For Ideal semiconductor switches, the anode-cathode conductivity.
-
For IGBT - collector-emitter conductivity.
-
For MOSFETs, the drain-to-source conductivity.
-
For Thyristor - anode-cathode conductivity.
Threshold voltage, Vth - threshold voltage
6 V (by default) | scalar
Threshold voltage for the gate-cathode circuit. The switch turns on when the gate-cathode circuit voltage exceeds this value.
For different types of switching devices, the threshold voltage is:
-
For the Ideal semiconductor switch, the gate-cathode voltage.
-
For IGBTs, the gate-emitter voltage.
-
For MOSFETs, the gate-source voltage.
Diode
These tables show how the visibility of the Diode parameters depends on how you have configured the Modelling option, Model dynamics and Reverse recovery time parameterization parameters.
| Parameters and settings | |||
|---|---|---|---|
*Modelling option |
|||
|
|||
*`Model dynamics |
|||
|
|
||
Forward voltage |
Forward voltage |
||
On resistance |
On resistance |
||
Off conductance |
Off conductance |
||
Junction capacitance |
|||
Peak reverse current, iRM |
|||
Initial forward current when measuring iRM |
|||
Rate of change of current when measuring iRM |
|||
*Reverse recovery time parameterization |
|||
|
|
|
|
Reverse recovery time stretch factor |
Reverse recovery time, trr |
Reverse recovery charge, Qrr |
|
*`Modelling option |
||||
`Synchronous converter |
||||
*`Model dynamics |
||||
|
|
|
||
Forward voltage |
Forward voltage |
|||
On resistance |
On resistance |
|||
Off conductance |
Off conductance |
|||
Junction capacitance |
||||
Peak reverse current, iRM |
||||
Initial forward current when measuring iRM |
||||
*Reverse recovery time parameterization |
||||
|
|
|
||
Reverse recovery time stretch factor |
Reverse recovery time, trr |
Reverse recovery charge, Qrr |
||
Model dynamics - diode model
Diode with no dynamics (by default) | Diode with charge dynamics | None
Diode type.
The following options are available:
-
None- this option is not available for non-synchronous inverter. -
Diode with no dynamics- select this option to prioritise the simulation speed with the Diode block. This option is used by default for non-synchronous inverter. -
Diode with charge dynamics- select this option to increase the accuracy of the model in terms of charge dynamics in reverse mode, using the switching diode model of the Diode block.
If Averaged Switch is selected for Switching Device in the settings, this option is not displayed and the Model dynamics parameter is automatically set to Diode with no dynamics.
|
Forward voltage - forward voltage
0.8 V (by default) | scalar
Minimum voltage required at the anode and cathode units to make the I-V characteristic gradient of the device equal to , where is the value of the On resistance parameter.
On resistance is the on resistance
0.001 ohm (by default) | scalar
The rate of change of voltage versus current is higher than the voltage set by the Forward voltage parameter.
Off conductance - Off conductance
1e-5 1/ohm (by default) | scalar
The reverse bias conductance of the diode.
Junction capacitance - junction capacitance
50e-9 F (by default) | scalar
The amount of capacitance inherent in the depletion junction, acting as a dielectric and separating the anode and cathode junctions.
Peak reverse current, iRM - peak reverse current at iRM measurement
-235 A (by default) | negative scalar
Peak reverse current measured by an external test circuit.
Initial forward current when measuring, iRM - initial forward current when measuring iRM
300 A (by default) | positive scalar
Initial forward current (at the initial switch-on time) when measuring peak reverse current. This value must be greater than zero.
Rate of change of current when measuring, iRM - rate of change of current when measuring iRM
-50 A/µs (by default) | negative scalar
Rate of change of current when measuring peak reverse current. This value must be less than zero.
Reverse recovery time parameterization - type of reverse recovery time definition
Specify stretch factor (by default) | Specify reverse recovery time directly | Specify reverse recovery charge
Specifies the method of specifying the reverse recovery time in the block. By default, Specify stretch factor is used.
Reverse recovery time stretch factor - the reverse recovery time stretch factor
3 (By default) | scalar greater than 1
The value 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.
Reverse recovery time, trr is the reverse recovery time
15 µs (by default) | scalar
The amount of time it takes for a diode to switch off when the voltage across it 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.
The interval between the time when the current initially becomes zero (when the diode turns off) and the time when the current drops to less than 10% of the peak reverse current.
Reverse recovery charge, Qrr - reverse recovery charge
1500 µCl (by default) | scalar
The value the block uses to calculate Reverse recovery time, trrr. Use this parameter if the block 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: * - the value specified for the Peak reverse current parameter, iRM.. * - is the value specified for the parameter Rate of change of current when measuring iRM.
LC Parameters
Inductance - inductance
1e-6 H (by default) | `positive scalar'.
Inductance.
Inductor series resistance - inductor series resistance
0 ohms (by default) | `zero or positive scalar'.
Inductor series resistance.
Capacitance - capacitor.
1e-7 F (By default) | positive scalar
Capacitor effective series resistance - capacitor resistance
1e-6 Ohm (by default) | zero or positive scalar
Series resistance of the capacitor.
Snubbers
The table shows the dependencies of the Snubbers parameters.
* Snubbers parameter dependencies |
|
Snubber |
|
|
|
Snubber resistance |
|
Snubber capacitance |
|
Snubber is the snubber model.
None (By default) | `RC snubber `
Model of the snubber switching device.
Snubber resistance - snubber resistance
0.1 (by default) | Ohm | scalar
Snubber resistance.
Snubber capacitance - snubber capacitance
1e-7 (by default) | F | scalar
Snubber capacitance.