Infinite Inductance Power Converter Question

Thread Starter

Bserar79

Joined Oct 24, 2018
22
Hello guys, and a great day to all of you!

Recently, while studying for an exam i came across something that still puzzles me. So, in my course i have this A.C. to D.C. half-wave rectifier, connected to what the teacher refers to as a a D.C. motor. So, everything okey, i understood the calculus behind everything, but at the end of the course, there is a question which i cannot understand.

upload_2019-3-24_23-9-51.png

It asks what happens if the inductor on the schema has an infinite inductance. From what i managed to understand until now, in this case, the inductor will act as a current source, as:

upload_2019-3-24_23-10-29.png

But now, how can i plug this into the circuits equation, as now i will get an Indeterminate:

upload_2019-3-24_23-12-24.png
So i think that's not the way to the solution. The biggest problem is that i can't understand the concept behind the question. An infinite inductor should opose to any current change, so if the initial current in the circuit is 0, it should remain that way, isn't it? I also tried to search in a book provided by the teacher, and i found a current plot for a full-wave rectifier, but is not really helpful, as it offers 0 explanations for the math behind:

upload_2019-3-24_23-18-35.png
So, can you help me a bit guys? I thinking about it for almost 3 days now, can't really find an answer. I also tried simulating the circuit, which got me an even bigger question. When i try to simulate it with a very high value inductor, the voltage on the inductor, after the diode is no longer rectified, and this just breaks my mind:

upload_2019-3-24_23-26-16.png
So, if you guys can help me i bit, i would be very grateful. Also, sorry is it's a very trivial question, but i just can't get my mind around it. Thanks a lot to everyone! :)


 
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