loss_angle
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loss_angle [2021/10/20 21:14] stanzurek [5. Compare losses] |
loss_angle [2021/12/20 23:16] (current) stanzurek [1. Set dummy model] |
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| Set up a simulation, in which a block of this material is magnetised in a uniform way, in the whole volume (e.g. thin sheet in a closed yoke). For ferrites this is easier, because eddy currents can be mostly neglected and the conductivity can be set to zero, so almost any shape will do. For conductive materials this is more difficult, because the sample has to be very thin so that the eddy currents are negligible. It is advised to set this up as a very thin lamination, for instance with the thickness less than 10x the skin depth (see also: https:// | Set up a simulation, in which a block of this material is magnetised in a uniform way, in the whole volume (e.g. thin sheet in a closed yoke). For ferrites this is easier, because eddy currents can be mostly neglected and the conductivity can be set to zero, so almost any shape will do. For conductive materials this is more difficult, because the sample has to be very thin so that the eddy currents are negligible. It is advised to set this up as a very thin lamination, for instance with the thickness less than 10x the skin depth (see also: https:// | ||
| - | A good geometry is a very thin cylinder (toroid), excited with a single turn of primary winding, inside the cylinder. A ratio of outer diameter to inner diameter OD/ID < 1.1 (like a pipe with a fairly thin wall) guarantees uniform magnetisation, | + | A good geometry is a very thin cylinder (toroid), excited with a single turn of primary winding, inside the cylinder. A ratio of outer diameter to inner diameter OD/ID < 1.1 (like a pipe with a fairly thin wall) guarantees uniform magnetisation, |
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| + | ^ Download | ||
| + | | **You can download a FEM example here: {{loss_angle_example.zip}}** | | ||
| The dummy model should be set such that the flux density is uniform. As shown in Fig. 3 this can be done with the toroidal sample, with the magnetising winding positioned exactly at the centre. There is no need for the returning wire of the coil. | The dummy model should be set such that the flux density is uniform. As shown in Fig. 3 this can be done with the toroidal sample, with the magnetising winding positioned exactly at the centre. There is no need for the returning wire of the coil. | ||
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| Use the block integral, and calculate '' | Use the block integral, and calculate '' | ||
| - | Adjust the value of loss angle (trial and error, etc.) until the loss density is the same as the calculated target value (11475 W/ | + | Adjust the value of loss angle (trial and error, etc. starting for example with a value of 1 deg) until the loss density is the same as the calculated target value (11475 W/ |
| Check the value of B, because it could change slightly. If it does, then just repeat the steps in another iteration (first adjust the current to set the B, then adjust the angle to set the loss). | Check the value of B, because it could change slightly. If it does, then just repeat the steps in another iteration (first adjust the current to set the B, then adjust the angle to set the loss). | ||
loss_angle.1634757251.txt.gz · Last modified: 2021/10/20 21:14 by stanzurek
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