DC to DC Converter

Demonstrative Video


Aim

To study the operation of DC - DC converters using MATLAB Simulink.

Converter topologies:

  1. Buck Converter
  2. Boost Converter
  3. Buck-Boost Converter

Simulation tools required:

MATLAB

Simulation Procedure:

  1. Construct the circuit in the MATLAB, Simulink.
  2. Use pulse generator to generate the gate pulses to the IGBT of the DC-DC converter.
  3. Configure the pulse generator as shown below.

    4. image
  4. The duty cycle of the converter is varied by changing the Pulse width in the pulse generator.
  5. Vary the duty cycle as shown in observation table above and note the output voltage values.
  6. Use the output voltage formula of each converter type to compute the output voltage calculated in the observation table. For example, considering a
    1. Buck-Converter, the output voltage can be expressed as \( V_o = D\cdot V_{in}\)
    2. Boost-Converter, the output voltage can be expressed as \(V_o = \dfrac{1}{(1-D)} \cdot V_{in} \)
    3. Buck-Boost Converter, the output voltage can be expressed as \(V_o = \dfrac{D}{D-1} \cdot V_{in} \)

Block Diagram of Buck Converter:


image

Pulse generator showing 40% duty cycle


image

Block Diagram of Boost Converter:


image

Block Diagram of Buck-Boost Converter:


image

Results:

Buck Converter

  1. Attach the circuit diagram of Buck - converter with R Load in MATLAB Simulink
  2. Attach the Simulated Waveforms at 40% duty cycle (Source voltage and current, Output Voltage and Current, Voltage across IGBT)
  3. Observation table:

    4. Sl. no

    Input

    Voltage (Vin)

    D, Duty

    Cycle =Ton / T (%)

    Calculated output voltage

    (V)

    Simulated output voltage

    (V)

    1

    20

    2

    40

    3

    60

    4

    80

Boost Converter

  1. Attach the circuit diagram of Boost - converter with R Load in MATLAB Simulink.
  2. Attach the Simulated Waveforms at 40% duty cycle (Source voltage and current, Output Voltage and Current, Voltage across IGBT)
  3. Observation table:

Sl. no

Input

Voltage (V)

D, Duty

Cycle (%)Ton / T

Calculated output voltage

Simulated output voltage

1

20

2

40

3

60

4

80

Buck-Boost Converter

  1. Attach the circuit diagram of Buck – Boost converter with R Load in MATLAB Simulink
  2. Attach the Simulated Waveforms at 40% duty cycle (Source voltage and current, Output Voltage and Current, Voltage across IGBT)
  3. Observation table:

Sl. no

Input

Voltage (V)

D, Duty

Cycle (%) = Ton / T

Calculated output voltage

(V)

Simulated output voltage

(V)

1

20

2

40

3

60

4

80