双极性与单极性ns级高压脉冲电源设计及特性比较

为了满足聚合类绝缘材料老化实验及等离子体水处理高级氧化实验2项实验研究的应用要求,分别设计了双极性和单极性2种ns级高压脉冲发生器,且均主要由高压直流电源、两级脉冲储能电容器和气体开关等组成,结构紧凑,具有重复频率、脉冲宽度及电压幅值可调等优点。2种脉冲电源的主要区别在于各自的核心元件—多电极旋转火花隙开关(MER-SGS)的结构和尺寸设计,同时电源的重复工作频率也可由旋转火花隙驱动电机及电极数量调节控制。为验证火花隙开关的工作性能,采用ANSOFT/MAXWELL ELECTROSTATIC 2D软件建立了仿真模型,对2种开关不同开断关合角度下的电场强度进行了仿真分析和比较。结果表明,火花隙的紧凑结构设计能够产生强烈电场畸变进而保证脉冲电源在具备良好输出特性基础上,开关可靠动作,从而达到降低绝缘要求、减少电极烧蚀、延长工作寿命等目的。通过对2种脉冲电源有载情况下实际输出波形的测量可得,脉冲上升时间(<10ns)、脉冲宽度(1～500μs)、重复工作频率(1～3kHz)、平均功率等电源参数均达到各自实验要求标准,具有良好的应用前景。

Design and Characteristic Comparison of Bipolar and Unipolar High Voltage Nanosecond Pulsers

To meet requirements of different experimental research application,such as polymer aging of dielectrics and wastewater treatment using discharge plasma,we designed a bipolar high voltage nanosecond pulser and a unipolar one,respectively.The main difference between two pulsers lies in their varied constitution and size of key part,multiple-electrode rotating spark gap switch(MER-SGS),of which the highest pulse repetition rate can be determined by DC driver motor revolution and electrode number.Calculating the distortion characteristic of electrical field can ensure enough action time,reduction ablation,and prolong the life of the switch.Moreover,we set up two simulation models for each MER-SGS.On the basis of the models,ANSOFT/MAXWELL ELECTROSTATIC 2D software was used to simulate,analyze,and compare the strength of electrical field of different action angle of two switches.Finally,we measured actual output waveforms under the conditions of two pulsers with load,and the results demonstrated that waveform characteristics,including rise time(<10 ns),pulse width(1~500 μs),repetition rate(1~3 kHz) and average power,etc,met the standards of experimental application,and both of two pulsers had vital prospects in application for their compact structure,low cost and good performance.