变负载电阻脉冲成形网络放电的初步分析

Primary Analysis of Pulse Forming Network Discharge with Time-varying Resistance

负载特性对脉冲成形网络的放电过程有直接影响,进而影响整个系统的发射效率。因此,建立了一个变负载电阻的脉冲成形网络放电计算模型,用于讨论回路的响应特性。并采用快速Fourier变换(FFT)方法探究了回路电流和负载电阻之间的内在关系。结果表明,实验和模拟计算的回路电流和负载电阻在频谱上都集中在低频率段。负载电阻的变化主要对回路电流的FFT相位有明显的影响。相对峰值电流随着负载电阻频率的增加做阻尼振荡变化,而与负载电阻的幅值存在线性关系,对于负载电阻初始相位呈现出正弦变化。特别是在短脉冲放电(电感很小时)过程中,相对峰值电流与负载电阻的振幅和相位有相反的变化。负载电阻对峰值电流的影响大约有±2%。负载电阻的振幅对回路电流峰值的影响超过其相位和频率对回路电流峰值的影响。

The characteristics of load always affect the discharging of pulse forming network （PFN）, and thus affect the emission efficiency of a launch system. We established a PFN discharge model with variable resistance to discuss the re- sponse characteristics. The fast Fourier transform （FFT） was employed to explore the intrinsic relationship between loop current and load resistance. Both experimental and numerical results show that the loop current and load resistance con- centrate in the band of low frequency. The change in load resistance mainly affects FFT＇s phase. The relative peak current has a damping oscillation with the frequency of load resistance and a linear relationship with the amplitude of load resis- tance, and it also has a sinusoidal change with the phase of load resistance. Particularly, the relative peak current negatively changes with the amplitude and phase of load resistance in short-pulse discharges （when inductance is small）. The influence of load resistance on peak current is around 2%. The amplitude of load resistance has more remarkable ef- fects than its phase and frequency on peak current.