为了在强电磁干扰环境中控制"双脉冲"实验的放电时序,研制了一台高电压同步控制系统。在采用多种常规的抗电磁干扰方法(如电磁屏蔽、光电隔离、独立电源和接地等)的基础上,该系统的核心抗干扰技术是选用高反向偏置的可控硅作为高电压脉冲变压器原边放电的控制开关。该系统由1个低电压多路时延发生器和5个独立的高电压脉冲发生器组成,它们分别放置在各自的电磁屏蔽机箱内,采用电池或电源隔离变压器供电,独立接地,时延发生器和高电压脉冲发生器之间采用光纤连接和光耦隔离。该系统可以输出5路25 kV的触发电压脉冲,各路之间时间间隔为0~1 s,最小调节时间步长为10 ns。该控制系统被成功地用于"双脉冲"放电实验中,实验证明它具有很好的抗电磁干扰能力。
In order to synchronize the high-current pulsed discharges in the "two-pulse" experiment in which high electromagnetic noise was produced,a high-voltage synchronization system was constructed.Being composed of one multi-channel time delay unit based on a field programmable gate array and five high-voltage pulse generators,the system could send out five 25 kV trigger pulses with time delays from 0 to 1s and a smallest time step of 10 ns.The time delay unit and each high-voltage pulse generator were separately put inside metallic boxes for electromagnetic shielding,grounded separately and powered by batteries or isolating power supply transformers.The time delay unit delivers the time delay signals through optical fibers to the high-voltage pulse generators.Furthermore,a highly negative biased thyristor was chosen as the switch that controls the discharge from an energy-storage capacitor to the primary of the high-voltage pulse transformer.The synchronization system was successfully used in the "two-pulse" experiment in which the electromagnetic noises were very strong,proving the system possessed a high noise-immunity.