Browsing by Subject "conductors"

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Calculation of Slot Losses in High Frequency Electrical Machines
(0000-00-00) Pratap, S.B.;
As new magnetic materials as well as applications emerge in electromechanical conversion systems, one finds that electrical machines are increasingly moving away from the mainstream power frequency to much higher frequencies. This shift is mostly being driven by the fact that for the same power a higher speed machine is smaller in size. Operating at higher frequencies has its advantages on size however one must ensure that this advantage is not offset by larger losses in the core as well as in the conductors carrying the high frequency currents. This paper discusses a method of calculating the slot losses in conductors. There are two aspects to this loss calculation, (a) most machines will have parallel conductors in a single coil, one must know the current distribution in these individual parallel paths and (b) the current in each conductor is not uniformly distributed through the cross-section but is skewed due to proximity and skin effects. Both these considerations must be accounted for when determining the dynamic loss factors.
Numerical analysis of Conductor Response to Fast-Rising, High-Current Pulses
(IEEE, 1989-06) Cook, R. W.; Bacon, J. L.
Synthesis, Selective Laser Sintering and Infiltration of High Super Tc Dual Phase Ag-YBa2Cu307-x Superconductor Composites
(1993) Agarwala, Mukesh K.; Bourell, David L.; Manthiram, Arumugam; Birmingham, Britton R.; Marcus, Harris L.
Fine, homogeneous dual phase Ag-YBa2Cu307-x composite powders were prepared by a simple colloidal sol-gel co-precipitation technique. Silver did not react with or degrade YBa2Cu307-x. Bulk porous samples of pure YBa2Cu307-x and Ag-YBa2Cu307-x were made from powders by Selective Laser Sintering. The porous parts were further densified by infiltrating silver into pores, resulting in a dense, structurally sound dual phase superconducting composite. Laser processing parameters were varied to obtain optimum microstructure. The laser sintered parts required oxygen annealing after infiltration to restore the orthorhombic, superconducting structure. X-ray diffraction and Tc measurements indicate some impurity phases present in samples processed under aggressive laser conditions.