Learning Forum

[jksince1996]

Hello,

I'm having an issue where the stranded ac losses are very high for just a simple 10 AWG copper wire of short length. The DC losses seem normal. With 75 A sinusoidal excitation, the losses reach nearly 0.5 kW. I've attached photos and a link to the file. Thanks!

 

 

akrishnan60/test (github.com)

[Timotheos Fetsis]

What is the frequency of the sinusoidal excitation?

Please visit Maxwell Help > Post Processing and Generating Reports > Plotting Field Overlays > Loss Quantities in order to obtain more information about the StrandedLossAC.

[jksince1996]

The frequency is 200 kHz.

[jksince1996]

Additional observations:

When I have two pieces of the helical copper wire in parallel, the losses increase when they really should decrease from the single piece of wire case. This is because of I^2 * R for the losses. The currents split for the same resistance, leading to a lower loss. However, the losses are greater for two parallel wires.

Link to simulation file (debug for one copper wire, debug2 for two copper wires): akrishnan60/test (github.com)

I've noticed that the losses are high at the beginning of the simulation at the microsecond timescale, then decreases to zero as time increases. Are these just solver startup issues?

Thanks.

 

[Timotheos Fetsis]

Hello, in a situation with that kind of high frequency, skin & proximity effects are induced. Thus the current flows in the outer layers and is distributed unevenly within the conductor, increasing the resistance.