【摘要】 超导直流限流器是维持柔性直流输电系统稳定运行的关键部件，其超导状态的维持需要低温系统支撑。本文对一台160 kV/1 kA超导直流限流器的低温制冷系统进行了优化设计。系统采用了三台大冷量斯特林制冷机，在77 K温度下每台能够提供1 000 W制冷功率，系统运行时两台用于正常运行，一台备用，以确保系统的可靠性和稳定性。通过设计新型液氮制冷箱，实现了在不停机情况下的蓄液、自增压和回液功能，有效减少了液氮消耗。同时利用一台15 m~3液氮储罐作为气相缓冲设备，与制冷箱相互配合，大大抑制了限流器内的压力波动。研究表明，优化设计显著提升了系统的稳定性与可靠性，能够确保超导限流器的长期稳定运行。更多还原

【Abstract】 Superconducting fault current limiter is a key component for maintaining stable operation of flexible DC transmission systems. The superconducting state is sustained by the cryogenic system. The cryogenic cooling system for the 160 kV/1 kA superconducting DC fault current limiter was designed and optimized. In the system, three high capacity Stirling cryocoolers were applied. Each of them is capable of 1 000 W cooling power at 77 K. Two cryocoolers were for daily operation and one was as a backup to ensure the reliability and stability of the system. Meanwhile, a new type of liquid nitrogen cold box was designed, integrating functions of liquid storage, self-pressurization, and liquid backflow without terminating liquefaction.This effectively reduced liquid nitrogen consumption. Additionally, a 15 m~3 liquid nitrogen storage tank was participated as a gas-phase buffer, which cooperated with the refrigeration box to effectively suppress pressure fluctuations in the superconducting fault current limiter tank. The results show that the optimized design can significantly improve the stability and reliability of the system, supporting the long-term stable operation of superconducting current limiters.更多还原