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

Abstract

This work presents simulation studies on superconducting jointless loops known as double crossed loop coils, made from partially slit and stacked REBCO tape segments. The objective is to investigate design parameters for a novel magnetic bearing application, trying to increase the (levitation force)/(tape length) ratio. The adopted simulation strategy is to model the tapes as one-dimensional current sheets with the current density written as integral equations solved by finite elements. For this recently developed type of coil, each current path must be modeled, thus every tape should be represented in the simulation, as shall be discussed. The results demonstrate how the coils’ performance varies non-linearly to the geometric parameters and that stacking the maximum number of tapes is not the only way to increase the levitation force. Their force curves also do not show the same behavior as expected for bulk ones, and an analysis is performed to relate it to the critical current sensitivity to the magnetic field. A more detailed investigation explains this behavior from the induced currents’ point of view in every loop of the stack. Comparisons between the simulation data and prototype tests prove that the chosen model can satisfactorily reproduce the measurements.

Physical principles of development of magneto-levitation systems based on the second generation high temperature superconducting composites (Review)

“…The work [47] presents the calculation of a magnet of captured flux based on the HTS-belt stacks with the record-breaking captured magnetic field over 17 T. The publications include many works presenting the associated electrodynamic and thermal calculations of HTSbelt stacks subject to their layered structure [47,79,152,153]. These works deal with 2G HTS-belt stacks in perpendicular magnetic field [79,152] or superconductive rings as elements of a levitation system [153,154]. For HTS-belt stacks, calculations of current distributions and captured magnetic fields were performed, as well as calculations of levitation forces for belt stacks with the height from 5 to 700 belts in a stack within a wide range of temperatures [54] (Fig.…”

“…One more option of HTS-rings are loops of HTSbelts. The work [154] presents generalized model for the homogenization of HTS-loop and double wafer (Fig. 32), as well as the calculation of the vertical force based on the levitation gap for loop-type configuration (Fig.…”

Физические Принципы Создания Магнитолевитационных Систем На Основе Высокотемпературных Сверхпроводящих Композитов Второго Поколения (Обзор)

“…В литературе широко представлены работы, в которых приводятся связанный электродинамический и тепловой расчеты стопок ВТСП-лент с учетом их слоистой структуры [47,79,152,153]. В данных работах в качестве элемента левитационной системы рассматриваются стопки 2G ВТСП-лент в перпендикулярном магнитном поле [79,152] или сверхпроводящие кольца [153,154]. Для стопок ВТСП-лент проведены расчеты распределений токов и захваченных магнитных полей, а также расчеты силы левитации для стопок лент высотой от 5 до 700 лент в стопке в широком интервале температур [54] при намагничивании.…”

“…Еще одним вариантом ВТСП-колец являются петли из ВТСП-лент. В работе [154] приводится обобщенная модель для гомогенизации ВТСП-петли и двойной галеты (рис. 32), а также расчет вертикальной силы от левитационного зазора для петлевой конфигурации (рис.…”

“…Концепция маломасштабного ВТСП-двигателя[165].Unit: mmFlux lines of Halbach permanent magnet array Линейный ВТСП-мотор на основе катушек из ВТСПлент и массива Халбаха[154].…”