基于EAST超导纵场线圈的换流分析

Analysis of Discharge Based on Toroidal Field Coils of EAST

先进超导托卡马克(EAST)是一个磁约束核聚变装置,其中,纵场线圈的额定储能接近300 MJ,一旦发生失超没有及时地进行保护,后果将是灾难性的,因此可靠的纵场线圈失超保护措施对于EAST至关重要。从纵场线圈的能量泄放途径着手,在确保纵场线圈焦耳积分满足要求的前提下,详细地阐述了换流的方案和开关的连锁控制。理论分析和实验证明,它们不仅能保护纵场线圈的安全,而且能可靠地保护纵场电源;二次换流方案的采用,降低了开关分断直流电弧的难度,提高了开关的使用寿命,它对超导储能设备和大电感负载的换流具有一定的借鉴作用。

As a fusion device, the rating charge energy of toroidal field （TF） coils of EAST is about 300 MJ, so it is very important for EAST to adopt a credible quench protection system to avoid damage to TF coils. In order to satisfy the requirements of joule integral of TF coils, a suitable discharge circuit for the huge energy must be found. Consequently, we focus on some kinds of schemes for discharge and the interlocking control for switches particularly. The double discharge is also chosen to solve the difficulty of breaker being disconnected for DC and to prolong the use life for breaker, which can he achieved at a lower arc voltage compared with the single discharge. The interlocking control scheme can both improve the reliability for protection and reduce the price for project, importantly, can set an accurate delay time, at which the backup breaker can not be disconnected in case the main breaker has been disconnected. Some analysis and experiments confirm that the chosen scheme can not only ensure the safety of TF coils, but also protect TF power supply timely. The results provide some references for the superconducting charge devices and the inductance loads.