A Novel Magnetic Bearing Using REBCO Double Crossed Loop Coils

Simulations of REBCO tape jointless double crossed loop coils with an integral equations method

“…A DCL coil is built by inserting one loop stack inside another, geometrically mirrored, giving its crossed-current paths at the coil heads, as seen in figure 1. More details concerning this geometry can be seen in [13]. Some notable advantages of this configuration when compared to conventional tape stacks are the greater flux linkage area, which allows greater current induction, and the tape's ab plane parallel orientation to the linked magnetic flux, which results in lesser critical current reduction due to magnetic field exposition.…”

“…One major drawback in this formulation is that, until now, it only allows a 1D representation of a two-dimensional (2D) problem and the coil head effects are neglected for the induced currents and forces. Since in this case we are interested in designing long coils [13], neglecting the coil heads is a valid approximation, although discrepancies should be expected. A complete, three-dimensional (3D) simulation is another computational challenge for the future.…”

“…More recently, a novel arrangement, called the double crossed loop (DCL), has been proposed, having the advantage of employing twice as much HTS tape for an equivalent flux linkage area than a single loop. In that work [13], the first prototype DCL coils were proposed and investigated in terms of magnetic levitation force interacting with a section of the MagLev Cobra PMG. However, the DCL coils have shown a different behavior than what was expected, namely, a levitation force tendency to decay, which has remained unexplained until now.…”

“…In such context, this work proposes to continue the study from the previous one [13], aiming to develop a new magnetic levitation system using DCL coils instead of YBCO bulks. In order to make such a substitution feasible, the (levitation force)/(tape length) ratio should be increased, thus simulations using finite elements method (FEM) are employed.…”

Passivity-Based Control Design for Magnetic Levitation System

“…Due to many advantages of magnetic levitation system, including absence of contact, low noise, low energy consumption, it has been widely used, such as magnetic levitation bearings [1], magnetic levitation trains [2], magnetic levitation wind turbines [3], magnetic levitation vehicle operation lines [4]. Magnetic levitation system is highly nonlinear unstable system, it is a strong need to control the suspension gap.…”