介绍了一台大型垂直极化有界波模拟装置所用中间储能电容器(简称中储电容器)的设计过程和实验结果.电容器采用基于元件和组件的模块化设计,呈锥台状结构,支撑壳体为真空工艺玻璃钢材料.电容器容值由模拟装置等效的二级脉冲压缩回路决定,取值为1.8 nF.电容器内部绝缘介质为十二烷基苯,外部绝缘介质为45#变压器油,设计耐压3?MV,其绝缘长度主要由元件的体绝缘特性决定.采用三维电磁仿真软件估算中储电容器与中储开关构成回路的电感为659?nH,接近于实测数据623?nH.电容器上脉冲电压的测量通过对电容器电流进行积分来获取,而电流的采集采用封装在SF6气体中的3个膜电阻并联后所构成测量模块实现.实际运行数据表明,中储电容器容值达到设计值,测量探头标定系数稳定,在工作电压3.1?MV条件下未发生绝缘问题.

常用的固体绝缘介质(如环氧树脂)作为体积绝缘介质时发生绝缘损坏后难以修复或更换,严重情况还会导致设备或部件报废,石蜡在较低温度下可以熔化和固化,能解决更换和修复难的问题,提高设备的可维护性.现今缺乏石蜡击穿场强的基础数据.为此以80号微晶石蜡为研究对象,使用了真空制样预处理方法,研究了80号微晶石蜡在直流稍不均匀场、正极性和负极性极不均匀场下的击穿特性.结果表明:80号微晶石蜡在直流稍不均匀场下平均击穿场强在200 kV/mm以上,在极不均匀场下极性效应显著;击穿后重复制备两次可以消除内部碳化通道,且击穿场强接近新制备试品击穿场强,具备可重复使用的潜质.

分析了同轴薄膜电容器电参数和结构参数之间的关系,提出了以单层同轴薄膜电容器个数、两侧锥角和内芯外径等参数为变量,以实现各个单层同轴薄膜电容器薄膜介质厚度差异最小化为目标的设计方法.设计了一种耐受电压为1 MV,电容为200 pF,电容器长度不大于400 mm,外径不大于300mm的同轴薄膜电容器.其中,单层同轴薄膜电容器为13个,两侧锥角为34°,内芯外径为140 mm.最后通过模拟计算验证了上述优化设计方法的合理性.

The radiation fields of transverse electromagnetic (TEM) horn as a nuclear electromagnetic pulse(NEMP) radiating-wave simulator, are simulated by parallel finite-difference time-domain(FDTD) method. The EMP's effects of different dielectric load are numerical studied and analyzed. The results show that comparing with the traditional TEM horn antenna the peak value of E z increases or decreases, but the FWHM never widen as TEM horn loaded by dielectric.

Surface electrical insulation performance is an important issue in pulse power devices. In order to investigate the surface flashover characteristics in an environment of high pressure SF6, a flashover experiment platform was established with nanosecond pulse voltage supply. The flashover characteristics of polymethylmethacrylate (PMMA) specimens with circular truncated cone shapes were subsequently determined under incremental SF 6 pressures from 0.2 to 1.0 MPa. As the angle of cone increased, the flashover voltage (FV) rose under low pressure condition, but fell at first and then rose at high pressure. The surface length and the field nonuniform factor were the main influences of FV with angle. In addition, the FV rose linearly at first and then reached its maximum when gas pressure increased, and it was easier to reach the maximum when the field nonuniform factor was higher. A high speed camera was also applied to get the photos at different period of flashover, and the luminous processes of flashover along different specimens were discussed in particle perspective.

For typical Tesla transformers with open magnetic-core, a novel coaxial design of the primary side using a mechanically controlled spark gap is introduced to obtain a more compact configuration. The primary winding has several alternative ports to vary the current distribution by changing the position of the capacitor component, and the entire primary circuit is built inside the outer cylinder. For this new primary configuration, we estimate the series parameters and ohmic losses: Polypropylene film capacitors and combined metallized film capacitors are used in the verification tests, and the former capacitor exhibits a lower parasitic resistance below 10 mΩ. The ohmic losses caused by the windings and spark gap are also considered. The results of the experiments show that the voltage gain has an 8.2% drop when the parasitic resistance of C1 increased from 10 mΩ to 24 mΩ, and we deduce that the contact resistance of this primary structure can be limited to below 10 mΩ according to the circuit analysis results and the verification test.

Due to its low-loss and high dielectric strength, polypropylene is widely used as electrical insulation material in pulse capacitors. In order to study its breakdown characteristics for nanosecond voltage pulses, an experimental setup was designed to generate voltage pulses with a 10%-90% rise time of 38 ns and a full width at half maximum of about 90 ns. Tests of the three polypropylene films with thicknesses of 12, 15, and 18 mu m were performed. In addition, hundreds of nanoseconds pulse and de voltage were also applied for comparison. The experimental results reveal that most of the breakdown occurs during the front edge of the pulse for tens of nanoseconds pulse, and the breakdown strengths of the three kinds of polypropylene films are almost identical for different applied voltages, which show a weak correlation between the thickness of the dielectric and the breakdown field. The expected breakdown strength of tens of nanoseconds pulse defined in this paper is not significantly higher than the mean value of the hundreds of nanoseconds pulse and the dc condition, suggesting that the breakdown of a thin polypropylene film is mainly determined by the electrical field but not the voltage-time cumulative effect. All these observations strengthen the conclusion that the breakdown of a thin polypropylene film is an intrinsic phenomenon.

Based on iterative expressions of Uniaxial anisotropic Perfectly Matched Layer(UPML) absorbing boundary for media with magnetic loss, a symmetrical method, combined with parallelized Finite Difference Time Domain (FDTD) method and perfect magnetic conductor(PMC) boundary condition, is presented in this paper. The examples of Bounded wave simulator(BWS) with distributed terminator are given. The results agree well with those of normal FDTD, and computing time is saved. The comparison of simulation with experiment is also offered. The method shown in this paper is universal for other BWS and antennas with symmetric tangential fields.

The radiation fields of little bounded wave electromagnetic pulse (EMP) simulator with lumped terminator, which used for biomedical experiment, are simulated by parallelized finite-difference time-domain(FDTD) method. The EMP's effects of two dielectric plates and plastic box in the little bounded wave simulator(BWS) are numerical studied and analyzed. The results agree well with the theory analysis. The results show that the peak values of the electric fields at center in the working volume of BWS increase as the depth of the two dielectric plates increases. And the electric fields in the plastic box decrease as the box existed.

A high power pulse generator is described,which has been used in a bounded-wave Electro Magnetic Pulse(EMP)simulator. The peak value of the generator output voltage is above 100 kV,the rise time of output waveform 1.8 ns,and its pulse-width 40 ns. The diameter of the generator is 18 cm,and its length 97 cm. The generator, with compact configuration,also can work in a repetitive mode. This system can be adopted to evaluate and improve the viability against Nuclear Electro Magnetic Pulse(NEMP) of weapons.

In field-distortion gas spark switch,discharge channel between two electrodes can be conducted rapidly in argon gap,as abundant metastable atoms excite in argon.In this paper,a series of experiments to support the superiority of spark gap using argon gas mixtures were accomplished.The discharge characteristics of gas mixtures(SF6-Ar and N2-Ar)in spark gap were obtained under DC voltage.On this basis,we can get the optimized argon percentage of gas mixtures and figure out the break-down characteristics of gas mixtures in spark gap.The spark gap using SF6-Ar can reach a lower jitter when the percentage of ar-gon is higher than 20%.However there is no ideal performance using N2-Ar mixtures.

In this paper,a 2 MV self-triggered switch with capacitance coupling circuit is presented under the microsecond pulse.The switch has a simple structure and a high reliabil-ity.Based on the electric field strength and circuit simulation,some key configurations and circuit parameters are obtained.The calculation results show that the voltage of designed triggered gap accounts for 1 .2 1% of the main gap,and the nonuniform factor of the main gap is 1.64,the breakdown voltage of the self-triggered gap is about 21 kV when the maxi-mum working voltage of the switch is 2.27 MV at the air pressure of 0.7 MPa.

The output switch is a key component which connects the pulse power generator and the antenna in an intense electromagnetic pulse simulator and its turning on and off can reflect the working condition of the simulator. In order to measure the turn-on time of the output switch, the formative time of the switch is analyzed based on avalanche and streamer theory, and the optical technique which provides a method via optical fiber transmission for penetrating into high voltage cavities with the advantages of insulation and electromagnetic interference is adopted. A measuring system based on optical fiber and silicon PIN detector is developed, and an experimental platform for testing the synchronous characteristics is established. The experiments are carried out using a one-to-one scale output switch model. The experimental results show that the measuring system is excellent in electromagnetic resistance, the start point of the measured optical signal is clear to recognize; the average time delay between start points of the optical signal and the current signal is 20.42ns, the range and the jitter of the time delay are 0.78ns and 0.4ns; the designed optical system can be used to monitor the turn-on time of the output switch.

To get the better choice for achieving higher stability and reproducibility of the output voltage pulse of the generator, two pancake switches commonly used in the low energy, high peak power Marx generator have been compared. The comparison is done in several aspects including the structure, the electric field distribution, and the breakdown characteristics. Some useful conclusions are drawn. And there is a big difference between the structural capacitances of the two gas switches as a result of the different configuration of their electrodes. So a circuit simulation of the switch used in a simple, basic, two-stage Marx circuit has been done on both switches respectively.

A new transmission line of“Spring-Thunder”bounded-wave EMP simulator is designed and constructed.The transmission line is 27 m long,10 m wide,and 6 m high,and adopts a subulate plank and distributed terminator structure.The transmission characteris-tics of the transmission line are measured and simulated.The results show that the reflected wave formed by terminal load chains of transmission line is added on the falling edge of wave-form which causes waveform distortion of HEMP.Meanwhile,the E-field shape is not uni-formity inside the working volume of the transmission line,and the maximum deviation of E-field strength is 1 8%.

An 100 kV compact Marx generator is designed and constructed,and it is presently operational at Northwest In-stitute of Nuclear Technology.In this paper the principle of compact Marx generator is introduced.Single polarity charge,ceram-ic capacitance,switch and insulation integrative configuration and function blocking are adopted to make Marx generator compact. The front part of the generator includes trigger,charge and gas pressure control module,and it can work reliably with gas source and AC input only.The Marx generator has a wide working range,with an output voltage range from 15 kV to 100 kV.

Ultraviolet (UV) illumination can effectively shorten the statistical lag and jitter in gas breakdown processes. The spark gap discharge can produce abundant spectrum including UV waveband. In this paper, a simple but reliable spark gap operating with N-2 at atmospheric pressure is used to test optical radiation characteristics, such as spectrum intensity, rise time, fall time, and duration of optical pulse, which are adjusted by changing the circuit or configuration parameters. Three UV-illuminated switches with different UV spark gap configurations have been tested. The experimental results approve our assumption. With a uniform electric field UV spark gap, the breakdown voltage standard deviation percentage of the switch is 0.74%.

实验研究了长60 m、宽20 m、高10 m的大尺寸TEM天线的传输特性,其脉冲源采用薄膜开关与天线一体化设计,输出电压幅值可达10 kV,上升沿约1.2 ns.实测了TEM天线内部的电场分布,研究了该大尺寸TEM天线中电场分布规律,给出了脉冲上升沿与传输距离的关系、脉冲幅值与传输距离的关系,总结了快沿双指数波在天线中传输的高频损耗特性,给出了实验空间的选择方法.研究结果表明:上升沿随传输距离呈线性增大趋势,两极板中间测点增大速度最快,传输50 m距离,上升沿增大约1.2 ns;电场幅值随传输距离呈指数减小趋势.