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Power Electronics - Engineering

Q1:

The turn on characteristics of a power transistor can be assumed to be linear, as shown in the below figure . During turn on time T, voltage reduces linearly from V to 0 and current rises linearly from 0 to I. The energy loss during time T is

A VIT

B

C

D

ANS:D -

Energy = integral of P with respect to t.

we can express i(t) = (I/T)t and v(t) = (-V/T)t + V.
P(t) = v(t)i(t) = (-IV/T^2)t^2 + (VI/T)t.
integral of (-VI/T^2)t^2 + (VI/T)t from 0 to T.
-VIT/3 +VIT/2 = VIT/6.