Research of High Voltage Superconducting Homopolar Machines

一般说来，同极电机不能实际应用，因为它们的输出电压太小。为了改善这一特性，我们引入了超导磁体的高磁场。此外，我们还介绍了一种多盘式电枢，它由多个旋转电枢盘串联而成。有两个电枢盘和一个超导场的实验机器。实验结果表明：(1)磁场不被电枢旋转盘屏蔽；(2)输出电压成为各电枢旋转盘电压之和。在实验研究的基础上，我们进行了额定500kV、500MW大型超导均极电机的概念设计。从设计研究中可以看出，采用这种同极电机的AC/DC变换器可以直接产生直流电，效率达到99.7%，大大高于一般的固定式变换器。有待解决的技术问题如下：(1)研制高性能集电流电刷系统；(2)增大旋转盘直径对提高输出电压非常有效；(3)建立杂散磁场屏蔽技术。

Generally, it has been said that homopolar machines cannot be applied for practical use because their output voltages are too small. In order to improve this characteristics, we introduced a high magnetic field of a superconducting magnet. And, we also introduced a multi-disk-type armature, which has many rotating armature disks connected in series electrically. An experimental machine with two armature disks and a superconducting field. The experimental results shows ;(1)the magnetic field is not shielded by the armature rotating disks,(2)the output voltage becomes the sum of each armature disk voltage,Apart from the experimental study, we carried out a conceptual design of a large scale superconducting homopolar machine with a rating of 500kV,500MW.From the design study, it becomes clear that the AC/DC converter using this homopolar machine can generate DC power directly with the efficiency of 99.7%, which is much higher than the usual stationary type converters.The technological problems left to be solved are listed below ;(1)the development of high performance current collecting brush system,(2)the increasing of the diameter of the rotating disk is very effective to increase the output voltage,(3)the establishment of shielding technology of stray magnetic field.