Unbalanced 3 Phase Problem

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Thread Starter

Daniel

I've been given a problem regarding a arc welder. It has three electrodes in a delta connection. Large amounts of current are pushed through the electrodes to heat them up. I've been given the task of creating a spreadsheet which calculates the resistance/impedances between the electrodes given the voltages between the lines as well as the line currents (measured). I have researched and I understand the concept of delta-star connections but I am battling with deriving the formula for the resistances/impedances. Any Help would be greatly appreciated. I will try post a sketch of the problem.

Thanks.
My email is [email protected]
 
Daniel... further to my earlier post, it is not easy to analyze arcing-current. But, if that is what you need, then it can be represented by a sparkover-gap device, having intermittent current flow for each 1/2-cycle of the sinusoidal driving voltage.

If you would like additional information let me know.

Regards, Phil Corso (cepsicon[at]AOL[dot]com
 
I'm working at a company and one of the power systems guys has given it to me as a project, but I think it's out of my league. That's why I'd appreciate any help. I'm a second year electrical engineering student.
 
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Daniel Fynes-Clinton

Phil... We have done differential equations and yes it is a demonstration unit for an electric arc furnace. I have tried using mesh currents and finding three equations for the resistors but it is quite meticulous to try isolate a formula for each resistor (R1, R2, R3). Am I on the right track, or is there an easier/better way? The help is much appreciated.
 
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