Project 1

The selected three topologies are

1) Buck converter in Continuous Conduction Mode(CCM)

2) Boost converter in Continuous Conduction Mode(CCM)

3) Inverting Buck-Boost converter in Continuous Conduction Mode(CCM)

Design

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Simulation

BUCK CONVERTER

As the input voltage is varying the step function is used to vary the input from 40 V to 50 V at t=0.0025 sec

Duty ratio D= 0.75 to 0.6 at t=0.0025 sec and generating accordingly the pulses to turn ON and OFF the MOSFET and thus to maintain the output voltage constant at Vo=30 V.

Results:

1.Output voltage and current waveforms:

1. From the above waveforms we can see the output voltage almost 30 V , And at t=0.0025 sec we can observe small overshoot during transient and settles down in the steadystate.
2. At t=2.5 msec , the input voltage is varied from 40 to 50 V. Here, the input current is pulsating DC waveform.
3. According to design requirement the inductor current ripple is maitained below 25% of Average inductor current and it is in Continuous conduction mode(CCM).
4. From the above waveforms we can observe that the maximum breakdown voltage of devices.

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BOOST CONVERTER

ZOOMED IN

• From the above , the output voltage is almost 40 V , at t=5 msec we can observe small overshoot during transient and settles down in the steadystate.
• At t=5 msec , the input voltage is varied from 20 to 30 V.
• According to design requirement the inductor current ripple is maitained below 25% of Average inductor current and it is in Continuous conduction mode(CCM).
• Here, the devices breakdown voltages are same and it doesnot depend on the duty ratio, it depends on the output voltage i.e., 40 V.

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BUCK BOOST

• The output voltage almost -45 V . At t=20 msec we can observe small overshoot during transient and settles down in the steadystate.
• At t=20 msec , the input voltage is varied from 30 to 60 V.Here, the input current is pulsating DC waveform. Hence, to make input a pure DC value we need to add the input filter.
• According to design requirement the inductor current ripple is maitained below 10% of Average inductor current and it is in Continuous conduction mode(CCM).
• with variation also, the output is almost constant with very small variation