A Buck Converter is a DC – DC step down voltage converter (can also be considered like step up current converter) .

Here is how you can use Matlab to simulate a Buck converter *(Note: In this post, we will consider switches as ideal)*

In order to get this task done in Matlab we will need the following component from Simulink Library.

Design a Buck converter in Matlab

## Main elements

### DC voltage Source

Amplitude voltage: 190 V

### A Pulse Generator

Amplitude: 1

Period (sec): 0.0001

Pulse width (% of period): 25

Phase delay (secs):0

Interpret vector parameters as 1-D: activated

### An Ideal switch

Internal resistance Ron (Ohms): 0.001

Initial state (0 to ‘open, 1 for ‘closed’): 0

Snubber resistance Rs (ohms): 1e5

Snubber capacitance Cs (F): inf

Show measurment port: activated

### A Diode

Resistance Ron (ohms): 1e5

Inductance Lon (H): 0

Forward voltage Vf (V): 0.8

Initial current Ic (A): 0

Snubber resistance Rs (ohms): 500

Snubber capacitance Cs (F): 250e-9

Show measurement port: activated

### An Inductor, a Capacitor and a Resistor

L=200e-6

C=300e-6

(All these 3 components are being added by using the element below, you just need to choose one or more to be included in your block/element)

## Additional elements

In order to visualize the behavior of different voltages and currents in the circuit, we will be using the following elements.

### Current measurement

### Voltage measurement

### Scope

Parameters

### Bus Selector

Parameters

### Powergui

Parameters

## Opening Simulink Library and creating a new model in Matlab

By clicking on the icon shown on the picture below, you can open Simulink library

The following should pop up

You can then easily create a new model with a click on the ** New Model **icon shown on the image above.

After opening the new model, draw the following

Most of the element are in * SimScape/SimPowerSystems* and in

*Library. You can use the research bar to find element in the library as well.*

**Simulink**Run the model, and check different wave shapes on each on the scopes.

My output voltage shape looks like this

Switch Current and voltage

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