Basic study on electrical insulation test method and electrical insulation design of HTS power devices

高温超导(HTS)功率器件的电绝缘系统一般放置在低温冷却剂池中。此外，超导体中的失超现象是不可避免的，如果由于超导体淬火部分的焦耳热而使冷却剂蒸发，其介电强度将显著降低。然后，必须在绝缘设计中考虑这两个因素，在高压试验中也要考虑这两个因素，以确保所设计的电气绝缘的可靠性。本文研究了高温超导功率器件在研制、制造和出货阶段的室温等效室温高压试验方法。提出了室温下等效绝缘试验电压的确定方法，并尝试将该方法应用于高温超导功率器件。特别是提出了估算等效绝缘试验电压的“中值因子”的基本参数，并通过模拟高温超导线圈元件和实际线圈的实验验证了该参数的有效性。

The electrical insulation system of the high temperature superconducting(HTS) power devices is generally placed in the pool of cryogenic coolant. Moreover, the quench phenomena are inevitable in it and its dielectric strength is significantly reduced if the coolant vaporizes due to the Joule heat at the quenched part of the superconductor. Then, these two factors must be taken into the insulation design, and also considered in high voltage tests to secure the reliability of the designed electrical insulation. In the present research, the equivalent high voltage testing method at room temperature for promising HTS power devices at the stages of development, manufacturing and shipment is studied. The determination method of the equivalent insulation test voltage at room temperature is proposed and the application of the method to the HTS power devices is attempted. Especially, the basic parameter of "Medium Factor" for the estimation of the equivalent insulation test voltage is proposed and its usefulness is confirmed by experiments using modeled HTS coil elements and real coils.