直流高压缓冲器的研制

Development of Iron Core Snubber

铁心缓冲器(core snubber)是中性束加热高压电源中最常用的一种抑制短路电流的装置,也是国家重大科学工程超导托卡马克聚变实验装置(EAST)的中性束注入器在高压打火故障时免于损坏的重要保障。为了研究所选铁心在高频脉冲放电情况下的特性,给设计提供依据,对测试件进行了短路放电测试。利用测量的电压电流得到了铁心的B-H曲线,并对有无偏置电流进行了比较;根据实验得到的参数设计了100 kV电源缓冲器,最后通过仿真对该设计进行了验证。结果表明装置中加入偏置电流后,可大大增加铁心磁通密度的变化幅度,起到增加铁心利用率的目的。设计得到的缓冲器可以将短路电流限制在预设的300 A之内。该电磁计算和高频放电测试得到的数据可为缓冲器设计提供参考,并可进一步为高压直流电网短路缓冲设计提供有效的技术手段。

Core snubber is one of the most important devices to protect the neutral beam injector（NBI） system during the breakdown period.To study the characteristics of the specified ferromagnetic material of the core in the high frequency discharge condition,the discharge voltage and current were measured.With the results,the B-H curve was then calculated.According to the derived parameters of the curve,the core snubber for a 100 kV NBI power supply was designed and simulated by MATLAB/SIMULINK.The results show that the bias current can enlarge the flux swing significantly.The designed snubber limits the short circuit current within 300 A.The magnetic analysis and the high frequency discharge test can shed more light on the design of the snubber of the high voltage DC power grid.