Eddy-Currents Simulations with Inflation Layers for Industrial ...

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IEEE Compumag Society: Team 21a ProblemMeshingTwo possible options: Uniform volume meshwith sufficiently smallelements to resolve eddycurrents confined in athin layer bellow theouter surface Thin inflation layersbellow the outer surfaceand volume mesh withlarger elements for therest of the body© ABB GroupJune 20, 2009 | Slide 6

IEEE Compumag Society: Team 21a ProblemResults80.00Solid117 Solid 236 IBC Infolytica70.0060.00Total power loss (W)50.0040.0030.0020.0010.000.000 100000 200000 300000 400000 500000 600000 700000Number of elements© ABB GroupJune 20, 2009 | Slide 9Results of the volume mesh approach (brute force) is presented.

IEEE Compumag Society: Team 21a ProblemComparison: Uniform Volume Mesh vs. Inflation LayersVolumemeshInflationlayers*Solid 117Solid 236Solid 117Solid 236* two layers, each 1 mm thickElementsize (mm)3366N ELEMENTS726’358726’358150’707150’707CPU time17min 58sec50min 28sec2min 38sec4min 43secP LOSS(W)23.720.318.6918.19(%)32%13%3.8%1%Solid117 Solid 236 IBC Infolytica80.0070.0060.00Total power loss (W)50.0040.0030.0020.0010.000.000 50000 100000 150000 200000 250000 300000 350000Number of elements© ABB GroupJune 20, 2009 | Slide 10

Simplified real-life problem: Busbars and TR TankModeling± 4000 A (50Hz, rms)Aluminum massivebusbars.Transformer tank: r= 150 © ABB GroupJune 20, 2009 | Slide 11B. Cranganu-Cretu, J. Smajic, G. Testin, “Usage of Passive Industrial Frequency Magnetic-FieldShielding for Losses Mitigation: A Simulation Approach”, Proceedings of the Advanced ResearchWorkshop on Transformers, Baiona, Spain, 2007.

Simplified real-life problem: Busbars and TR TankMeshingN E= 678’384CPU time:1h 1min 41sec© ABB GroupJune 20, 2009 | Slide 12

Simplified real-life problem: Busbars and TR TankMeshingN E= 678’384CPU time:1h 1min 41sec© ABB GroupJune 20, 2009 | Slide 13Inflation layers: two layers, each 1 mm thick

Simplified real-life problem: Busbars and TR TankResults© ABB GroupJune 20, 2009 | Slide 14Real part of magnetic induction B (T) is presented.

Simplified real-life problem: Busbars and TR TankResults© ABB GroupJune 20, 2009 | Slide 15Real part of eddy-currents density (A/m 2 ) is presented.

Simplified real-life problem: Busbars and TR TankResultsInfolyticaIBCElementsize (mm)10N ELEMENTS1’283’494CPU time13 minP LOSS(W)1254(%)-© ABB GroupJune 20, 2009 | Slide 16Inflationlayers*Solid 117Solid 236* two layers, each 1 mm thick1010678’384678’38430min 51sec1h 1min 41sec862115331%8%

Simplified real-life problem: Busbars and TR TankResultsPoor accuracy with Solid 117 Very good accuracy with Solid 236InfolyticaIBCElementsize (mm)10N ELEMENTS1’283’494CPU time13 minP LOSS(W)1254(%)-Inflationlayers*© ABB GroupJune 20, 2009 | Slide 17Solid 117Solid 236* two layers, each 1 mm thick1010678’384678’38430min 51sec1h 1min 41sec862115331%8%

Conclusions Uniform volume mesh approach (brute force) appearsto be impractical for the eddy-currents analysis ofconductive highly permeable materials Inflation layers radically improve the accuracy andreduce the CPU time of the eddy-currents simulations Solid 117 is not recommended for tetrahedral mesheven if the inflation layers are used Solid 236 with inflation layers is a good bases forlarge-scale eddy-current simulations aimed at couplingwith CFD, thermal and mechanical analysis© ABB GroupJune 20, 2009 | Slide 18

© ABB GroupJune 20, 2009 | Slide 19