Trial production and experiment of linear actuator with double-sided primary and HTS bulk secondary

It is expected that HTS bulk materials are applied to various electric devices. In a previous work we have fabricated and tested a linear actuator with single-sided primary and HTS bulk secondary. The linear actuator was comprised of zero-field-cooled YBCO bulk for secondary (mover) and copper windings with iron core (primary). The primary was excited by a three-phase VVVF power source to provide sinusoidal traveling field. To improve the characteristics of the linear actuator, we newly designed and fabricated a linear actuator with double-sided primary and zero-field-cooled HTS bulk secondary. We measured starting thrust force and magnetic field distribution in the air gap between the bulk and the primary iron core at the stationary state. To evaluate dynamic characteristics of the linear actuator, we numerically investigated electromagnetic behavior within the bulk exposed to time-varying magnetic field using a simulation program based on the finite element method (FEM) taking the voltage-current (E-J) characteristic into consideration. Computed starting thrust force, displacement characteristic and field distribution between the bulk and the primary iron core were compared with the experimental results. Agreement between experiments and analyses was good. We also investigated the electromagnetic characteristics as a linear synchronous actuator with double-sided primary and field-cooled HTS bulk secondary.