Study of High Stable Magnetic Field by Superconducting Transformer

超导变压器高稳定磁场研究

基本信息

批准号：
16560245
负责人：
OTABE Soji
金额：
$ 1.28万
依托单位：
Kyushu Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2006
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-16560245/
关键词：
Superconducting Transformer DC mode Coupling Coefficient Time Constant

项目摘要

In 2004, DC transport current was tried to be induced by 500A class superconducting transformer. However, since the superconducting transformer was design to obtain high current, it was difficult to hold DC current for long time. In 2005, a new superconducting transformer was designed and fabricated in order to hold DC current for long time even though the magnitude of the current was small. The transport current induce in secondary winding was measured by the voltage at the low resistive shunt resistor inserted in the secondary winding. The current at the first winding of the superconducting transformer was controlled by PID method. For the result, the controlled time was extended to about 1 second. The control accuracy was within plus minus 0.4%. This value is far from 1 ppm which is required by NMR and MRI.In 2006, the accurate of current was tried to be improved by the knowledge obtained in previous studies. It is necessary to correctly measure the current induced in the secondary winding in order to obtain the stable current. Therefore, the magnetic field induced in the secondary windings was measured by a hole sensor and a pickup coil. The current of the first windings was controlled by the measured current of the secondary windings. As the result, the pickup method was better than the hole sensor method, and the more accurate control was established.In summary, the DC mode of the current induced in the secondary winding of the superconducting transformer is performed and confirmed. The methods to obtain stabilized magnetic field and current were proposed and performed. It is considered that these methods will be applied to many kinds of superconducting apparatuses. For example, the present knowledge will be applied to NMR and MRI facilities to obtain high stability magnetic field.

2004年，尝试用500A级超导变压器感应直流输电电流。然而，由于超导变压器是为了获得大电流而设计的，因此很难长时间保持直流电流。 2005年，设计并制造了一种新型超导变压器，即使电流幅度很小，也能长时间保持直流电流。次级绕组中感应的传输电流是通过插入次级绕组中的低阻分流电阻器上的电压来测量的。超导变压器第一绕组的电流采用PID方法控制。结果，控制时间延长至1秒左右。控制精度在正负0.4%以内。这个值与NMR和MRI所要求的1 ppm相去甚远。2006年，我们尝试通过以往研究中获得的知识来提高电流的准确度。为了获得稳定的电流，必须正确测量次级绕组中感应的电流。因此，通过霍尔传感器和拾波线圈测量次级绕组中感应的磁场。第一绕组的电流由测量的次级绕组的电流控制。结果表明，拾取方法比孔传感器方法更好，并且建立了更精确的控制。综上所述，对超导变压器次级绕组中感应电流的直流模式进行了执行和确认。提出并实施了获得稳定磁场和电流的方法。认为这些方法将应用于多种超导装置。例如，现有的知识将应用于核磁共振和核磁共振设备，以获得高稳定性的磁场。