基于高温超导的高精度电压互感器研究OACSTPCD

The excitation error of voltage transformer is caused by the voltage drop of the excitation current in the winding of voltage transformer,which is the main source of the error of voltage transformer.The two-stage excitation technology can ef-fectively reduce the excitation current of the voltage transformer,but the winding impedance cannot be eliminated,and the excitation error still exists.In this paper,77 K high temperature superconductivity technology is applied to voltage trans-former(HTS-VT),the winding and transformer core are working in high temperature superconducting environment,when the superconducting state is reached,the impedance of the winding is zero,and the voltage drop caused by the excitation current through the winding is also zero,which can fundamentally eliminate the excitation error.The copper loss and core magnetic properties of HTS-VT areanalyzed.The hysteresis and eddy current loss of the core are analyzed theoretically and the suppression measures are put forward.The core and winding structure of a voltage transformer with a ratio of 1 kV/10 V are designed.A prototype of HTS-VT voltage transformer isdeveloped.The low temperature Dewar container and its ex-ternal cold screen aredesigned to reduce the heat loss temperature field,and the temperature field simulation iscarried out to analyze the temperature distribution gradient.Finally,its errors arecalibrated,and the calibration results show that the ratio error of the prototype is better than 4 x 10-6 and the phase error is better than 5 μrad in the rated voltage range of 20％～120％,which is an order of magnitude smaller than that of the normal temperature voltage transformer.77 K high temperature superconducting voltage transformer is of great significance for improving the precision of voltage transformer,and can also provide theoretical support for the development of higher voltage grade superconducting transformer.