为了满足脉冲电场消融的应用需求,解决单极性脉冲电场分布不均匀的问题,研制了一台基于半桥结构的主电路、具有纳秒级前沿的高重复频率双极性亚微秒高压脉冲电源.该脉冲电源由FPGA提供控制信号,经过驱动芯片放大控制信号后,利用光耦隔离驱动多个SiC MOSFET.驱动电路所需元器件较少,信号控制时序简单,可提供负压偏置,使开关管可靠关断,提高了电路的抗电磁干扰能力,使电源能稳定运行.通过电阻负载实验,对比分析了不同栅极电阻对驱动电压的影响,驱动电压上升沿时间越短对应的双极性高压脉冲前沿越快.实验结果表明:所设计的高频双极性脉冲电源在 100 Ω纯阻性负载上能够稳定产生重复频率双极性纳秒脉冲,输出电压0~±4 kV可调,脉宽0.2~1.0 μs可调,正负脉冲相间延时0~1 ms可调,上升沿和下降沿60~150 ns之间.该双极性脉冲电源电路设计结构紧凑,能满足应用的参数需求.
To meet the application requirements of pulsed electric field ablation and solve the problem of uneven distribution of unipolar pulse electric field,a bipolar submicrosecond high voltage pulse power supply with high repetition rate and nanosecond front based on the main circuit of half-bridge structure was developed.The pulse power supply is provided by the FPGA control signal,after amplifying the control signal by the driver chip,the photocoupler is used to drive multiple SiC MOSFETs.The drive circuit requires less components,its signal control timing is simple,and it can provide negative voltage bias,so that the switch tube is reliably turned off,which improves the anti-electromagnetic interference ability of the circuit,guranteeing stable operation of the power supply.Through resistance load experiment,the influence of different gate resistors on the driving voltage is compared and analyzed.The shorter the driving voltage rise time,the faster the bipolar high voltage pulse front is.The experimental results show that the designed high-frequency bipolar pulse power supply can stably generate repetitive bipolar nanosecond pulses on 100 Ω pure resistive load.The output voltage is adjustable from 0 to±4 kV,the pulse width is adjustable from 0.2 μs to 1.0 μs,the phase delay between positive and negative pulses is adjustable from 0 to 1 ms,and the rising edge and falling edge are between 60 ns and 150 ns.The design structure of the bipolar pulse source circuit is compact,which can meet the application parameter requirements.