直线变压器驱动源模块输出电流上升时间调节

针对磁驱动等熵压缩实验对加载电流波形的特殊需求,基于改造后的1MA直线变压器驱动源(LTD)原理性模块,开展了输出电流上升时间调节实验研究。48只开关分为4组,由4根高压电缆引入触发脉冲分别触发,共进行了三组不同电缆长度组合的触发放电实验。结果表明:在±32kV充电电压下,输出电流上升时间(0~100%)可由301.2ns增加至436.0ns,相应的输出电流幅度由294.0kA下降至210.2kA。实验还采用光纤探针阵列测试系统同时对其中40只多间隙气体开关的放电发光过程进行了诊断,获得了相应开关的闭合导通起始时间。基于实验参数,利用PSpice电路模型进行了校验,并对早期触发的支路组对后续触发支路组的影响进行了分析。实验初步验证了LTD模块内部子块通过分时放电实现输出波形调节的能力。

Shaping of output current rise time on 1 MA-LTD cavity

For the special need of wide variety of current waveforms during the magnetically driven isentropic compression experiment, this paper describes experiments that can shape the output current rise time on a refurbished 1.0 MV linear transformer driver(LTD) cavity. Forty-eight switches were divided into four groups, and each group of switches were triggered by one high voltage cable. Three sets of trigger cables with different length were conducted. The experimental results show that 0~100% rise time of output current can increase to 436.0 ns compared with 301.2 ns when all the switches are triggered simultaneously. However, the peak current will decrease from 294.0 kA to 210.2 kA with initial charge voltage of 32 kV. The closing time of forty switches were achieved by using fiber diagnostics system which could measure the switch optic signal during the discharge state. Based on the closing time of forty switches acquired in the experiment, the circuit model of 1 MA-LTD cavity was constructed in PSpice. The influence of the brick that has been triggered early in LTD cavity to other bricks was analyzed. This preliminary experiment results show that the LTD cavity can shape the output pulse with the aid of different trigger sequence.