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Impedance calculation

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In a 2D axisymmetric model using MEF physics, I have a simple RLC coil group. I'm interested in both the inductance and capacitance of the coil.

COMSOL provides mef.LCoil_1 as a global post-processing value, but does not provide capacitance as a post-processing value. No problem, I figure I'll just calculate it using

C = 2*intWe/(mef.VCoil_1^2)

Naturally, I decided to double-check the inductance value using

L = 2*intWm/(mef.ICoil_1^2)

but this gives exactly 1/2 the value mef.LCoil_1 provides. So can someone help me with the missing factor of 2?


1 Reply Last Post 30.01.2015, 13:49 GMT-5

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Posted: 10 years ago 30.01.2015, 13:49 GMT-5
Okay, I figured it out. Because these are AC fields, not DC, the energy is time averaged. The average field is the RMS amplitude (1/sqrt(2)). The energy goes as the average field squared, and thus a factor of 1/2 from the DC formulation.
Okay, I figured it out. Because these are AC fields, not DC, the energy is time averaged. The average field is the RMS amplitude (1/sqrt(2)). The energy goes as the average field squared, and thus a factor of 1/2 from the DC formulation.

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