Boost converter

Switched step-up chopper; fire drives the transistor.

  • Boolean
  • electrical
  • Modelica Standard Library
  • 5 ports
  • 2 parameters
BlockBoost converterKindboostConverterLibraryConverters

Description

The switches of a step-up (boost) chopper: a transistor across the input (dc_p1 to dc_n1) and a diode from dc_p1 to dc_p2. dc_n1 and dc_n2 are the same node.

The block has no inductor. Put an inductor in series between the source and dc_p1, and a capacitor across the output.

Example

DC-DC converters Buck, boost, and bidirectional half-bridge converters switching at 10 kHz with 50 % duty.

Duty A 0.5PWM 10 kHzC A 100 µFLoad A 10 Ωv out A24 VGround (buck)BuckL 1 mHDuty B 0.5PWM 10 kHz (boost)C B 100 µFLoad B 50 Ωv out B12 VGround (boost)L 1 mH (boost)BoostDuty C 0.5PWM 10 kHz (half-bridge)C C 100 µFLoad C 50 Ωv out C12 V (half-bridge)Ground (half-bridge)L 1 mH (half-bridge)Half-bridge
In Gradara, select a Boost converter block and press F1, then choose Open example. It opens as a new model in My models, ready to run.

Also in this example:DC voltageVoltage sensorConstantGroundResistorCapacitorInductorBuck converterBuck-boost converterPWM generator

Ports

Inputs 1

  • firefire_pBoolean

    Transistor gate (Boolean). True shorts dc_p1 to dc_n1 through the transistor.

Conserving terminals 4

  • in+dc_p1electrical

    Input positive terminal: the switch node. Connect it to the source through the boost inductor.

  • in−dc_n1electrical

    Input negative terminal, connected internally to dc_n2.

  • out+dc_p2electrical

    Output positive terminal (diode cathode).

  • out−dc_n2electrical

    Output negative terminal, connected internally to dc_n1.

Parameters

  • Transistor on resistanceRonTransistor0.00001 Ω

    ≥ 0

    On resistance of each transistor, in ohms. 0 or more.

  • Diode on resistanceRonDiode0.00001 Ω

    ≥ 0

    On resistance of each freewheeling diode, in ohms. 0 or more.

Equations

Modelica
fire_p true: v1 ≈ 0, the inductor charges from the source
fire_p false: the diode carries the inductor current to dc_p2
Continuous conduction, duty cycle d: mean(v2) ≈ vsource / (1 − d)

Implementation

Modelica Standard Library 4.1.0Modelica.Electrical.PowerConverters.DCDC.ChopperStepUp
MSL documentation

Assumptions and limitations

  • Ideal switches: transistors are GTO-type switches that conduct only forward, and diodes switch at 0 V. Off conductance is fixed at 10 µS and knee voltages at 0 V. No switching times, reverse recovery, or conduction voltage drop beyond the on resistance.
  • Without an external series inductor, turning the transistor on shorts the source.

See also

Select a block in Gradara and press F1 to open its page offline.