GATE 2024 EE – Question 64
In the DC-DC converter shown in the figure, the current through the inductor is continuous. The switching frequency is 500 Hz. The voltage ($V_o$) across the load is assumed to be constant and ripple free. The peak inductor current in amperes is __________ (rounded off to the nearest integer).
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Correct answer: 13
Explanation
This is a boost converter with $V_i=20$ V and $V_o=40$ V, so $D=1-\dfrac{V_i}{V_o}=0.5$ and $T=2$ ms. The load current is $I_o=40/10=4$ A, so the average inductor (input) current is $\dfrac{I_o}{1-D}=8$ A. The ripple is $\Delta I=\dfrac{V_iDT}{L}=\dfrac{20\times0.5\times2\text{ ms}}{2\text{ mH}}=10$ A peak-to-peak. The peak current is $8+\dfrac{10}2=13$ A (the minimum, 3 A, is positive, so conduction is continuous).