🧨Measuring Magnetizing (Excitation) Current🧨
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- Опубліковано 15 жов 2024
- A quick video describing a simple method for measuring the magnetizing (excitation) current of a potential transformer. This test is performed on the high voltage windings of an energized transformer, under no-load conditions. Care should be taken to ensure proper isolation of oneself and all equipment used during the testing process.
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Love your videos man
Nice to see a vid from you mate👍👍
Quality content finally.
Agree !
Conceptually, I want to agree with those conclusions but I’ve recently done a similar experiment and am running into some issues that perhaps someone can rectify.
Using an LRC meter, I measured the inductance of the high voltage winding of a 2kva control transformer. The inductance was 0.6 Henry. Using the 2πfL formula, that gives an reactive impedance of 2π(60)(.6) = 226ohms. The winding resistance was 2 ohms, making for a total impedance of 228ohms.
The applied voltage was 120V rms. Using rearranged ohms law (i= v/Z) that should yield a excitation current of 120V/228ohms = 0.5amps. However, when I measure excitation current, the actual measurement is an order of magnitude lower (0.04 amps).
To be that low, the actual impedance must be something closer to 3000ohms instead of the 228 ohms that was empirically measured.
Assuming both LRC and ammeter are correct, does anyone have thoughts on this discrepancy?
That's very curious indeed. I'm not an engineer, unfortunately, so I'm not sure why your LRC meter showed such a low inductance. But if the transformer was open circuit, and the meter was applied to the high side, the value of L should have been much much higher.... as you indicated by the empirical data. Maybe make sure the meter isn't being "fooled" by something trivial like parasitic capacitance? Not sure if that would affect the accuracy of the measurement... but it's worth investigating.
Really love the video!
Awesome ⚡⚡
The amount of inductance surprised me. I couldn't believe it was that high! But that's what makes great experiments. 😄
What's the difference between complex and scalar? I thought they were the same thing
Complex vs real? Or scalar vs vector? Not sure which you mean. All magnetizing current (as well as capacitive current) is complex because expressing it mathematically uses imaginary numbers.
@@MegavoltHomeschool It was just from the ohm's law for AC equation at 1:36, that the quantities are expressed in complex, not scalar form.
@@phild.1122 yes, I see why its confusing. Basically it's saying pure resistance is scalar because its always in phase with current. Vectors are not needed to show phase angles. Once reactance is included, numbers become complex and vectors are needed.