Technology creation of HTS magnet for superconducting magnetic energy storage

就储能密度而言，螺线管线圈的储能密度较大。另一方面，环形磁场线圈的漏磁最小。高温超导SMES线圈的首要考虑是在保证超导线圈性能的同时降低成本，为此，所需的高温超导带长度需要尽可能短。高温超导带材的临界电流和n值取决于磁场及其与带材的夹角。因此，需要对高温超导带缠绕磁体的性能进行综合分析。根据Bi2223/Ag带材的测量值，通过对临界电流和n值的拟合方程，分析了高温超导线圈的伏安特性。分析了4种线圈布置方式的储能能力，以寻求最短的高温超导带材长度。由12个单元线圈组成的环形磁场线圈需要比螺线管线圈长58%的高温超导带材才能储存100kJ的能量，但中面0.01T的漏磁场区域约为螺线管线圈的一半。两极线圈和四极线圈的这些特性介于两者之间。

As for the stored energy density, the solenoid coil has the larger value. On the other hand, the toroidal field coil has the least leakage flux. The primary concern of HTS SMES coil is the reduction of the cost, while securing superconducting coil performance.For this purpose, the required HTS tape length needs to be as short as possible. The critical current and n values of HTS tapes depends on the magnetic fields as well as its field angle to the tapes. Therefore, the performance of magnets wound with HTS tapes needs to be analyzed based on above factors. The current-voltage characteristics of the HTS coil were analyzed by means of fitting equations of the critical current and n value obtained from the measured values of the Bi2223/Ag tape. The stored energy of four kinds of coil arrangement was analyzed, thereby pursuing the shortest length of HTS tapes.The toroidal field coil comprised of 12 element coils requires 58% longer HTS tapes than the solenoidal coil to store the energy of 100 kJ, but 0.01 T leakage field region at the mid-plane is about a half of the solenoid coil. These properties of two-pole coil and quadrupole coil are situated between them.