Development of Fully Superconducting Thrust Linear Actuator Using Temperature Superconductors

在本项目中，我们研究和开发了具有高温超导（HTS）初级绕组的全超导线性执行器和由高温超导体制成的推进器的基本技术。大推力电动直驱直线执行器在工业自动化领域具有巨大的潜在需求。电力直接驱动系统可以实现快速准确的力控制，这是液压系统和齿轮马达系统等其他方法难以实现的。然而，为了使用铜绕组的电直接驱动系统获得高推力，绕组的电流密度应该非常高，绕组中的焦耳加热变得非常高。因此，执行机构需要大容量的电源和大尺寸的水冷却系统。另一方面，与铜作动器相比，全超导作动器结构更紧凑，推力更大，功率损失更小。它只需要小尺寸的电源，冷却系统可以比铜执行器的水冷却系统小得多。制作了一种以铋/银包覆带为主绕组的作动器模型和YBCO本体的推力器模型，并对推力的基本原理进行了研究。建立了计算推力的解析模型，并验证了解析模型的有效性。我们还研究了一次绕组和大块超导体的交流损耗特性，这是设计作动器的重要数据。我们开发了一种用于推力器的可选极性体阵列磁化方法，并证明了该方法的有效性。

In the project, we studied and developed elementary technology for fully superconducting linear actuators with high temperature superconducting (HTS) primary windings and a thruster made of HTS bulks.An electric direct-drive linear actuator with high thrust force has great potential needs in the field of industrial automation. Rapid and exact force control is possible by the electric direct-drive system, which is difficult by other methods such as hydraulic system and gear-and motor system. To obtain high thrust force using an electric direct-drive system of copper windings, however, current density of the windings should be very high and the joule heating in the windings becomes very high. Therefore, the actuator needs a large capacity power supply and a large size water cooling system. On the other hand, the fully superconducting actuator can be more compact and have higher thrust force with much smaller power loss than the copper actuator. It only needs small size power supply and the cooling system can be much smaller than the water cooling system for the copper actuator.We made a model actuator with a primary winding wound of Bi/Ag sheathed tape and thruster with a YBCO bulk and studied basic of thrust force.We made an analytical model to calculate the thrust force and showed the validity of the analysts. We also studied AC loss characteristics of the primary windings and the bulk superconductors which are important data for designing the actuator. We developed a method to magnetize a bulk array with alternative polarity for the thruster and proved the method worked well.