3-D Modeling of Coils for Pulsed Field Magnetization of HTS Bulk Pellets in an Electrical Machine

Abstract

Abstract-In this work, we propose to study and design a coil used to magnetize, by means of a Pulsed Field Magnetization (PFM) process, an inductor of a radial flux superconducting machine with one pair of poles. Each pole contains four similar HTS bulks of 30 mm diameter arranged in a square pattern. The cryostat already exists for this application and the temperature of the HTS bulks can vary from 4.2 K to their critical temperature, in transient state. For a given primary source of energy, here a capacitor bank of 10 kJ (5 mF, 2 kV) is available, the PFM process depends strongly on the value of the coil inductance used to generate pulsed field, because it defines the waveform of the current: peak value and time constant. Thus, 3D modeling of the coil is required in order to be sure that its inductance and the magnetic field produced will provide a full magnetization of HTS bulks. From the practical point of view, we would like to achieve an average magnetization of each pole around 3 T.In this paper, numerical modeling of coils with different number of turns coupled with circuit's equations is achieved. The maximum magnetic field obtained on the HTS bulks and estimated magnetization at the top center of each HTS bulk, are presented and discussed.

Modeling of vortex dynamics in HTSs with defects under the impact of pulsed magnetic field

“…The interest in studying the magnetic properties of hightemperature superconductors (HTSs) is growing every year. Numerous studies have shown that bulk superconductors and stacks of HTS tapes are capable of trapping magnetic fields of several teslas or higher and can therefore be used as pseudopermanent trapped field magnets (TFMs) [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. The range of potential practical applications of such magnets extends from magnetic bearings and levitation devices to motors and highfield magnets [1,2,16,[19][20][21][22][23].…”

What Formulation Should One Choose for Modeling a 3-D HTS Motor Pole With Ferromagnetic Materials?

“…H(Ω) is the finite dimensional subset of the curl-conform space H(curl; Ω) generated by Whitney edge elements on the mesh in Ω [5]. (H 3 (Ωm)) 3 is the space of piecewise constant vector functions (3 components) per element in Ωm. * For the ā-formulation, choosing σ = 0 in Ω C c makes the system singular, but this is not necessarily an issue as some linear solvers do not require uniqueness of the solution.…”

Flux Pinning Docking Interfaces in Satellites Using Superconducting Foams as Trapped Field Magnets

“…Additionally, a fuel cell could be used to power the coils as described in [26]. All the superconducting pellets used in the TF-FPDI must be equipped with a coil system wrapped around them [27] to allow for PFM (violet rings in Figs. 3 to 5).…”