【在 s******7 的大作中提到】 : : 自己讲不清楚就甩一句google :) : If you cannot explain it simply, you really do not understand it well : --Albert Einstein
s*o
53 楼
我倾向于这个答案,要看电流频率在整个系统self resonant频率的哪一边
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【在 s******7 的大作中提到】 : : 自己讲不清楚就甩一句google :) : If you cannot explain it simply, you really do not understand it well : --Albert Einstein
n*h
54 楼
I read his question again. The systems use a constant current source. Well, first I guess he meant constant amplitude AC current source, DC constant source won't have practical meaning in transformer. The system loss definitely goes higher. But if the question is about the loss in primary coil: If current flows into primary coil is constant, then the loss in it should be constant, at first order. It is I^2*Rp. This assumes frequency is not too high and every component is still in their comfortable range. (analysis at extreme conditions may not be useful anyway.) However, because the image L reduces primary coil inductance. The voltage across the primary coil should reduce. The extra loss from supply source is from the extra phase shift between V/I in primary coil. If V/I is in 90 degree shift, there is no loss. The extra phase shift is caused by the loss in image inductor. If image inductor is lossless, this problem becomes a bit hard since it will require a bit calc/simulation. You may have to run some simulation to know the exact answer. This question is either an interview question, or a question from people doing electric motor driver.
【在 s******7 的大作中提到】 : : 自己讲不清楚就甩一句google :) : If you cannot explain it simply, you really do not understand it well : --Albert Einstein
s*n
55 楼
同意你最后一段。既然楼主还执着于线圈本身损耗这样的概念性问题,估计是面试时候 问到的。
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【在 n******h 的大作中提到】 : I read his question again. The systems use a constant current source. Well, : first I guess he meant constant amplitude AC current source, DC constant : source won't have practical meaning in transformer. : The system loss definitely goes higher. But if the question is about the : loss in primary coil: : If current flows into primary coil is constant, then the loss in it should : be constant, at first order. It is I^2*Rp. This assumes frequency is not too : high and every component is still in their comfortable range. (analysis at : extreme conditions may not be useful anyway.) : However, because the image L reduces primary coil inductance. The voltage