水中脉冲放电振荡特性分析及抑制方法研究

Research on circuit oscillation and its suppression method generated by high-voltage discharge in water

水中脉冲功率放电过程中产生的电路振荡,会延长放电时间,降低储能电容寿命。为了对电路振荡进行抑制,首先根据脉冲功率放电装置工作环境,利用COMSOL仿真软件,建立了二维轴对称高压放电模型,模拟了11 kV下电极间隙为4 mm下的高压击穿过程,并分析了等离子通道电导率变化趋势。然后建立等离子通道二维阻抗模型,对电极上的实际放电波形进行了非线性回归分析,得到其电阻和电感分别为0.439Ω和19.8729μH。最后根据负载特性提出了用脉冲功率晶闸管来抑制电路振荡的策略,并进行了脉冲功率放电实验。实验表明,通过理论阻抗计算得到的电极电压与实际放电电压相符合,且使用晶闸管脉冲功率开关可有效地抑制电路振荡,使振荡时间由220μs降低到36μs,降低了83.6%。

The circuit oscillation generated by high-voltage discharge in water not only prolongs the discharge time but also brings potential hazards to the service life of the energy storage capacitor.To solve this problem,a two-dimensional axisymmetric model was established using COMSOL software based on the working environment of the device,the high-voltage breakdown process with an electrode gap of 4mm at 11 kV was simulated,and variation trend of the conductivity of the plasma channel was analyzed.Then,a two-dimensional impedance model of the plasma channel was built.The actual discharge waveform on the electrode was analyzed based on the nonlinear regression method,and the resistance and inductance values were obtained,which are 0.439Ωand 19.8729μH,respectively.Finally,a strategy of using the pulse power thyristor to suppress circuit oscillation was proposed.The experimental results show that the electrode voltage waveform calculated based on the theoretical impedance was consistent with the actual discharge voltage.The proposed method of using the thyristor-based pulse power switch to suppress circuit oscillations was very effective,and the oscillation time was reduced from 220μs to 36μs,a total reduction of 83.6%.