inquiries about magnetostatic FEM simulation
inquiries about magnetostatic FEM simulation
(OP)
Dear friends: my name is andres felipe zuñiga I am from Cali, Colombia. I am simulating shortcircuit forces in transformers and busbars using FEMM software. I am analyzing the results from a scientific paper but I have differences with my results.
I am simulating a three phase busbar disposition with magnetostatic module
the dimensions of the busbar are:
width 6mm
height 75mm
long 1000mm
separation among phase bars 7.12mm
current densities in t=0s
current density phase A=77.66A/mm^2
current density phase B=-38.83A/mm^2
current density phase C=-38.83A/mm^2
maximun lorentz force in t=0s
Phase A=-7524N
Phase B=6120N
PhaseC=1405N
current densities in t=3.333ms
current density phase A=38.83A/mm^2
current density phase B=38.83A/mm^2
current density phase C=-77.66A/mm^2
maximun lorentz force in t=3.333ms
Phase A=-1405N
Phase B=-6120N
PhaseC=7524N
results reported by article
maximun lorentz force:
Phase A=6578N appearing in t=0s
Phase B= 7051N appearing in t=3.333ms
Phase C=6578N appearing in t=3.333ms
The author in the article performed a time step simulation with f=50hz using Opera Software
I am performed a magnetostatic simulation and comparing the results by time instant using FEMM Software
in theory, the maximum shortcircuit forces are obtained in middle phase conductor (PhaseB), anybody can advice me about what is wrong in this simulation?
thanks a lot
I am simulating a three phase busbar disposition with magnetostatic module
the dimensions of the busbar are:
width 6mm
height 75mm
long 1000mm
separation among phase bars 7.12mm
current densities in t=0s
current density phase A=77.66A/mm^2
current density phase B=-38.83A/mm^2
current density phase C=-38.83A/mm^2
maximun lorentz force in t=0s
Phase A=-7524N
Phase B=6120N
PhaseC=1405N
current densities in t=3.333ms
current density phase A=38.83A/mm^2
current density phase B=38.83A/mm^2
current density phase C=-77.66A/mm^2
maximun lorentz force in t=3.333ms
Phase A=-1405N
Phase B=-6120N
PhaseC=7524N
results reported by article
maximun lorentz force:
Phase A=6578N appearing in t=0s
Phase B= 7051N appearing in t=3.333ms
Phase C=6578N appearing in t=3.333ms
The author in the article performed a time step simulation with f=50hz using Opera Software
I am performed a magnetostatic simulation and comparing the results by time instant using FEMM Software
in theory, the maximum shortcircuit forces are obtained in middle phase conductor (PhaseB), anybody can advice me about what is wrong in this simulation?
thanks a lot





RE: inquiries about magnetostatic FEM simulation
RE: inquiries about magnetostatic FEM simulation
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The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.
RE: inquiries about magnetostatic FEM simulation
I am not well versed in principles and standard assumptions for short circuit force analysis, but it strikes me that the actual inrush current waveforms for the three phases could be a challenge to predict. This is where the time-stepping simulation was probably required. But if you start with those currents specified (from a time stepping simulation), then you should be able to predict associated magnetic forces vs time from the currents vs time and from geometry without consideration of dynamics (magneto quasi static analysis).
OP - When you did your analysis, you should have set up current A in the opposite direction from B and C. (did you do that?)
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(2B)+(2B)' ?
RE: inquiries about magnetostatic FEM simulation