Electromagnetic forces in Three Phase Copper Busbars (Rectangular)

[benyzk]

Homework Statement

So here is the Problem :

I am Modelling an interesting problem for a project i am busy with. I need to find out the force exerted on a single busbar in a 3 phase system, with each phase carrying 3300A.

This is mainly so that i can deduce what size of busbar supports i should be using so as to handle the worst case scenario induced magnetic forces between the busbars. Assume a short circuit current of 25KA.

i am attaching a very simplified model of the problem to this post.

i have also modeled the problem using FEMM (which i will attach to the post as well) and from there i am able to calculate the forces between the busbars in the using the force from stress tensor function. For anybody who is familiar with this force, can i assume this force to be that between the busbars


Also my second problem is that the model assumes that there is 3300A running through the busbars with the Go current and -3300 running through the busbars in the return Busbars (during normal operations) However, this is not true, because in 3 phase, the currents will be offset by 120 degrees at any point in time. What effect(Magnetically) does this have on the busbars? does the force remain the same as though the current in the phases is 0 degrees apart?




Any help / brainstorming will be greatly appreciated folks. Thank you.

 

[member 553083]

Homework Equations I'm not sure exactly what equations you would use to solve this problem, but I suggest looking up the equations used to calculate magnetic fields and forces. This includes: Magnetic Flux Density (B), Magnetic Field Strength (H), and Magnetic Induction (A/m). You may also want to look into the equations for calculating current density (J) and emf (V). These equations should give you the information you need to calculate the forces exerted on the busbars.