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Buck Converter

Implement buck power converter

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  • Buck Converter block

Libraries:
Simscape / Electrical / Specialized Power Systems / Power Electronics

Description

The Buck Converter block implements a buck power converter. You can choose from four model types:

  • Switching devices — The converter is modeled with IGBT/diode pairs controlled by firing pulses produced by a PWM generator. This model provides the most accurate simulation results.

  • Switching function — The converter is modeled by a switching-function model. The switches are replaced with two voltage sources and two diodes on the AC side and with two current sources on the DC side.

    The converter is controlled by firing pulses produced by a PWM generator (0/1 signals) or by firing pulses averaged over a specified period (PWM averaging: signals between 0 and 1). Both modes of operation produce harmonics normally generated by a PWM-controlled converter and also correctly simulate rectifying operation as well as blanking time. This model type is well-suited for real-time simulation.

  • Average model (D-controlled) — The converter is modeled using a switching-function model directly controlled by the duty cycle signal (0 < D < 1). A PWM generator is not required.

  • Average model (D-controlled, no rectifier mode) — The block uses the voltage source directly controlled by the reference voltage to model the converter. The model does not require a PWM generator and does not simulate the rectifier mode. This setting provides the fastest simulations.

    When doing real-time simulation, use the Switching function setting with the firing pulses averaged, or the Average model (D-controlled) or Average model (D-controlled, no rectifier mode) settings.

Examples

Power Converters Modeling Techniques

Power Converters Modeling Techniques

The operation of several types of power electronics converters that can be simulated using one of four selectable modeling techniques

Ports

Input

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Input port to block all firing pulses to the converter. To block all firing pulses to the converter, apply a signal value of 1 to this port.

The firing pulse signal to control the converter.

Dependencies

To enable this port, set Model type to Switching devices or Switching function.

The duty cycle signal (a value between 0 and 1) used to control the converter.

Dependencies

To enable this port, set Model type to Average model (D-controlled).

Conserving

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Specialized electrical conserving port associated with the converter's positive terminal.

Specialized electrical conserving port associated with the converter's negative terminal.

Specialized electrical conserving port associated with the converter's output electrical terminal.

Parameters

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Specify the model type for the block to use.

Internal resistance of the switching devices, in ohms.

Dependencies

To enable this parameter, set Model type to Switching devices.

The snubber resistance, in ohms. Set the snubber resistance to inf to eliminate the snubbers.

Dependencies

To enable this parameter, set Model type to Switching devices.

The snubber capacitance, in farads. Set the snubber capacitance to 0 to eliminate the snubbers.

Dependencies

To enable this parameter, set Model type to Switching devices.

The forward voltage of the switching device and of the diode, in volts.

Dependencies

To enable this parameter, set Model type to Switching devices.

Internal resistance of the diodes, in ohms.

Dependencies

To enable this parameter, set Model type to Switching function or Average model (D-controlled).

The snubber resistance, in ohms. Set the snubber resistance to inf to eliminate the snubbers. This parameter is available only when you set the Model type parameter to Switching function or Average model (D-controlled).

Dependencies

To enable this parameter, set Model type to Switching function or Average model (D-controlled).

The snubber capacitance, in farads. Set the snubber capacitance to 0 to eliminate the snubbers.

Dependencies

To enable this parameter, set Model type to Switching function or Average model (D-controlled).

Forward voltage, in volts, across the diode when it is conducting.

Dependencies

To enable this parameter, set Model type to Switching function or Average model (D-controlled).

The snubber resistance across the two current sources, in ohms. Set the snubber resistance to inf to eliminate the snubbers.

Dependencies

To enable this parameter, set Model type to Switching function or Average model (D-controlled).

Snubber resistance across the two current sources, in ohms. Set the snubber resistance to inf to eliminate the snubbers.

Dependencies

To enable this parameter, set Model type to Switching function, Average model (D-controlled), or Average model (No rectifier mode).

Source resistance on the AC side, in ohms. Set the snubber resistance to inf to eliminate the snubbers.

Dependencies

To enable this parameter, set Model type to Average model (No rectifier mode).

Extended Capabilities

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

Version History

Introduced in R2015b

See Also

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