超导同步调相机低温系统设计与试验研究

超导同步调相机是一种用于电力系统的新型动态无功补偿设备，具有高效、快速响应等优点.本文描述了10 Mvar高温超导同步调相机的总体结构，励磁绕组采用YBCO高温超导带材绕制而成，通过循环的20 K冷氦气进行冷却.低温系统主要包含3台制冷机、1台氦气泵、冷头换热器及其他辅助设备，通过旋转密封装置与电机转子部分进行连接.本文重点介绍了低温系统的设计方法，包括转子、绝热力矩管和电流引线等关键部位漏热和氦气管路流阻的计算方法，并通过多次降温试验进行实验验证.通过对带负载试验结果分析得出：存在最优的氦气压力和氦气泵转速运行参数，使得电机转子部分获的最佳冷却效果.通过与300 kvar高温超导同步调相机的耦合测试发现，所研制的低温系统可将转子系统冷却至22.4 K,满足调相机应用中对低温环境的要求.

Design and Experimental Study on Cryogenic System of Superconducting Synchronous Condenser

Superconducting synchronous condenser is a new type of dynamic reactive power compensation equipment for power system, which has the advantages of high efficiency and fast response. This paper describes the overall structure of 10 Mvar HTS (high temperature superconducting) synchronous condenser. The excitation winding is wound with YBCO HTS tape and cooled by circulating 20 K cold helium. This paper focuses on the design method of the cryogenic system, including the calculation method of heat leakage at key parts such as rotor, adiabatic torque tube and current lead, and the calculation of t|he flow resistance of helium pipeline, which are verified by several cooling tests. Through the analysis of the load test results, it is concluded that there are optimal helium pressure and helium pump speed operating parameters, which make the motor rotor obtain the best cooling effect. Through the coupling test with 300 kvar HTS synchronous condenser, it is found that the rotor system can be cooled by the developed cooling system to 22. 4 K, which can meet the requirements of low temperature environment in the application of superconducting synchronous condenser.