Operational characteristics of linear synchronous actuator with field-cooled HTS bulk secondary

It is expected that HTS bulk materials will be applied to various electric devices. We have fabricated and tested a linear synchronous actuator with double-sided primary and HTS bulk secondary. The linear actuator consists of a field-cooled YBCO bulk for secondary (mover) and copper windings with iron core as a primary. The primary, which was excited by a three-phase VVVF power source to generate sinusoidal traveling magnetic field, was divided into two sections: 1) the starting section in which the secondary is accelerated as an induction machine; and 2) the synchronous section in which the secondary moves with a specified synchronous speed. As the secondary, two field-cooled bulks were arranged in certain interval. In this paper, for various intervals of bulks, we experimentally investigated the static characteristic in points of synchronous thrust force and the pull-in characteristics. And we developed a simulation program based on the finite element method (FEM) to investigate electromagnetic behavior within the bulk exposed to the magnetic field generated by the primary winding. We investigated the influence of the size, the number, and the interval of bulks on the static characteristic in points of synchronous thrust force by using the developed computer program.