高温超导变压器高压绕组的绝缘设计和试验

为了研究630kVA/10.5kV三相高温超导变压器雷电冲击情况下的绝缘问题,设计研制了一台与630kVA超导变压器高压绕组1∶1的模型。导线采用与超导变压器所用高温超导Ag合金包套不锈钢加强Bi2223多芯带材同样尺寸的CuNi合金带材,导线以聚酰亚胺薄膜采用双半叠包工艺进行绝缘。高压绕组模型为多层圆筒式结构,层间置有层间绝缘和冷却通道。液氮温度77K下远高于国家规定的该电压等级标准(75kV)要求的155kV,雷电全波冲击试验、波过程的测量试验以及对波过程仿真计算的结果表明,测量结果和理论计算结果比较吻合,冲击电位分布接近线性,没有形成震荡,为630kVA/10.5kV高温超导变压器的成功研制提供了依据。

Insulation Design and Test of High Voltage Winding for High Temperature Superconducting Transformer

A single winding model,same size and structure with the high-voltage winding of a three-phase 630 kVA/10.5 kV high-Tc superconducting(HTS)transformer,was developed and tested at liquid temperature 77 K in order to study high-voltage insulation in the case of lightning impulse.CuNi tape was adopted for the model winding and had same dimension with the multifilamentary Ag-alloy sheath Bi2223 HTS tape which was used in windings of practical HTS transformer.Insulation of CuNi tape was realized by technique of half-double wrapping up Kapton film,the type of high-voltage winding was solenoid with multi-layers among which there were layer-insulation and cooling paths.The wave-process and full-wave lightning impulse tests were performed in liquid nitrogen temperature of 77 K in high-voltage Lab.,TBEA Shenyang Transformer Group.The results show that the full-wave lightning impulse withstand voltage is 155 kV which is much higher than the National Standard of 75 kV.The wave-process of the winding is theoretically simulated and the calculated results are well in agreement with those of test,the impulse voltage distribution is approximately linearity and no vibration appears.The results provide reliable bases for the development of the 630 kVA/10.5 kV HTS transformer.