Study on Thermally-Controlled Superconducting Device for Synchronous Rectifier of Line Frequency

对超导电力电子器件的关断特性进行了测试，研究了制约超导电力电子器件实用化的触发能量降低问题。作为器件研制的第一步，我们尝试了如下方法制作沟道-栅结：(1)提出了NbTi表面覆铜层的氧化。我们试着制作沟道和绝缘层。(2)提出了一种气相沉积的方法。我们尝试在NbTi沟道和栅层上制作绝缘层。(3)用聚四氟乙烯片在一定温度下对NbTi箔和NiCr箔进行粘接试验。形成槽道-绝缘体-闸门桩结构。(4)整理了装置的基本特性、整流等数据，并在国际会议等会议上作了介绍。(5)我们在国际会议等会议上报道了降低通道与闸门之间热阻的试验情况。(6)揭示了…在移动流量泵上的下一步应用。并在应用超导会议和日本电气工程师学会会刊上作了介绍。研究结果揭示了“热控超导开关”用于整流装置的可能性。因此，有必要对降低关断能量进行研究。没有开关效率的提高，就没有可行性。在本项目下建立了薄保温层的施工方法。对模型开关进行了性能试验，为对比加热器效率的提高提供了标准数据。此外，(1)该可控整流装置由多层超导体、绝缘体和加热器组成。对于每个薄层，导热系数都较小。为了提高开关效率，建立了产生低热阻的绝缘层和加热层的方法。(2)制作出开关损耗最小、恢复时间为几毫秒的线频器件。(3)明确开关特性与结构(设计)参数之间的关系。(4)建立了带超导变压器的同步整流电路的电路结构。(5)通过对氧化物超导电性的特性评价，探讨其应用的可行性。为了制作开关器件，我们提出了科研资助项目(B)(2)“用于工频同步整流的热控超导电路及装置的研究”。较少

Turn-off characteristics test of the superconducting power electronics device has been performed.Loss reduction of the trigger energy, which is obstacle for practical use, has been studied. As first step of device development, we tried to make the channel-gate junction as follows ; (1) We proposed the oxidization of the clad copper on the surface of NbTi. We tried to make the channel and the insulator layer. (2) We proposed a vapor deposition method. We tried to make the insulator layer on the NbTi channel and the gate layer. (3) We tried to glue NbTi foil and NiCr foil with Teflon sheet under certain heat. It forms the channel-insulator-gate pile structure. (4) We arranged the data such as basic characteristics of the device and rectification, and presented at the international conference etc. (5) We reported at international conference etc. on the trial to reduce the thermal resistance between the channel and the gate. (6) We revealed next application on moving flux type flux-pump un … More der rotating condition, and presented in Applied Superconductivity Conference and The Transactions of The Institute of Electrical Engineers of Japan.Obtained results reveal the possibility of "Thermally-Controlled Superconducting Switch " for rectifying device. The study on reducing turn-off energy is requied. There is no feasibility without improvement of switching efficiency. The method of thin insulation layer are established under this project. Performance test of the model switch has been proceeded, and the standard data for comparing improvement of heater efficiency. Furthermore, (1) This controlled rectifying device consists of the multi-layer of superconductor, insulator and heater. With each of thin layer, less thermal conductivity is preferred. To improve switching efficiency, establish the method to yield the insulator and heater layer with low thermal resistance. (2) Fabricate the device which operate under line frequency with minimum switching loss and a few milli-seconds recovery time. (3) Clear the relationships of switching characteristics and the structural (design) parameters with many R＆D devices. (4) Establish the circuit configuration of the synchronous rectifier circuit with the superconducting transformer. (5) Investigate the feasibility to apply the oxide superconductivity, through its characteristics evaluation. To fabricate switching device, we proposed Research Project Grant-in-Aid for Scientific Research (B)(2) "Study on Thermally-Controlled Superconducting Circuit and Device for Synchronous Rectifier of Line Frequency". Less