行波电压叠加器的电路模型与输出特性

Circuit Model and Output Characteristics of Traveling Voltage Adder

为了研究行波电压叠加器(TVA)的输出特性以及影响输出特性的因素,将传输线和放电支路进行简化,给出了传输线、放电支路、屏蔽电极与外筒体间的分布电感与分布电容等参数的计算方法,建立了8级串联TVA电路模型。通过仿真得到了8级串联TVA驱动匹配负载时的输出特性,研究了开关闭合时序与分散性以及传输线阻抗等对输出特性的影响。仿真结果表明:当每级开关触发闭合时序为理想感应电压叠加器(IVA)时序时,传输线输出电压峰值随串联级数n的增长近似线性增长,电压脉冲前沿逐级陡化,在匹配负载上的输出电压为899 kV,脉冲前沿与第一级相比缩短10 ns;屏蔽电极上的电压峰值逐级减小,电压波形存在高频振荡;开关闭合时序对TVA传输叠加与输出特性有显著影响,TVA按理想IVA时序触发时的匹配负载电压前沿比同时触发时要陡,相差约50 ns,随着触发时序系数增大(>1),脉冲前沿逐渐陡化;当开关触发闭合分散性增大时,输出脉冲重复性变差;随着传输线阻抗从匹配阻尼增大至3倍阻尼,匹配负载电压峰值增大,前沿缩短约30 ns,波尾时间增大约200 ns。研究结果可为TVA型脉冲功率源装置的结构优化和研制提供一定的参考。

In order to study the output characteristics of the traveling voltage adder(TVA),and the factors that influenced the output characteristics,with the transmission line and the discharge bricks simplified equivalently,the methods are developed to calculate the parameters of the distributed inductances and the distributed capacitances between the transmission line,the discharge bricks,the shielding electrodes and the outer ground cylinder.And then the circuit model of an 8-stage series TVA is established.The output characteristics of the 8-stage series TVA and the effects of switch closure timing sequence and its dispersion,and transmission line impedance on the output characteristics are obtained,when the 8-stage series TVA is driven to a matched load.The results show that when the triggering sequence is an ideal induction voltage adder(IVA)sequence,the peak output voltages of the transmission line increases approximately linearly with the increase of series n,the leading edge of the voltage pulses are gradually steepened.The generator can deliver 899 kV fast pulse into a matched load.The leading edge is shortened by 10 ns compared with the first stage.The peak voltage on the shielding electrodes decreases with the increase of the series number of stages,and the voltage waveforms have a high frequency oscillation.Switch closure timing sequences have a significant impact on TVA transmission superposition and output characteristics.The load voltage leading edge when the TVA is triggered with an ideal IVA timing sequence is about 50 ns steeper than that with triggering simultaneously.As the trigger timing sequence coefficient increases(>1),the leading edge of the pulse gradually becomes steeper.With the augmentation of switch closure time dispersion,the repeatability of output pulse becomes worse.As the impedance of the transmission line of TVA increases from matching damping to 3 times damping,the peak voltage on the matched load increases,the pulse leading edge is shortened by about 30 ns,and the pulse tail time is increased by about 200 ns.This work can provide valuable reference for the structure optimization and development of TVA pulse power source device.