【作者】 张华；

【导师】 杨汉武； 张自成；

【作者基本信息】 国防科学技术大学 ， 物理电子学， 2010， 硕士

【摘要】 介质的绝缘性能对脉冲功率系统的性能起着关键作用。本论文对蓖麻油在不同电极条件、不同脉冲重复频率以及不同液体静压强等条件下对蓖麻油在微秒脉冲尺度下的绝缘性能进行了研究,并分析了蓖麻油在Tesla型脉冲发生器中的应用。论文主要包括以下几个方面:1、蓖麻油击穿系统的设计与仿真设计制作了一套液体介质耐压性能测试试件,试件结构合理,可以0.01 mm精度调节电极间距,并包含击穿电压、电流测量探头。对实验中经常出现的干扰、击穿试件高压端表面放电以及电极间介质状态的保持等问题,分别采用了屏蔽、浸油以及采用油循环等方法予以解决。仿真结果与实验结果趋势一致。2、蓖麻油击穿影响因素统计分析采用Weibull分布模型研究了击穿的概率分布。在均匀场作用下,测得蓖麻油的直流击穿场强约为20 kV/mm,单脉冲击穿场强约为73.5 kV/mm;极不均匀场情况下,针电极为正电极时击穿电压高于针电极为负电极情况,并且得到了击穿场强分别正比于正、负电极有效面积的-0.27及-0.18次幂。随着重复频率增加,蓖麻油的击穿电压呈下降趋势,击穿场强正比于重复频率的-0.12次幂。在液体加压情况下,击穿场强正比于所受静压强的1/4次幂关系,表明压强对蓖麻油的影响比对去离子水的影响更加显著。3、蓖麻油在Telsa型脉冲发生器的应用传统Tesla型发生器采用变压器油绝缘,根据蓖麻油的特性分析了系统参量的优化,并开展了实验研究。实验测得单次脉冲条件下负载输出电压为332.6 kV,输出脉宽10 ns,PFL最大充电电压为397.8 kV,负载输出功率为1.08 GW。重频条件下输出电压稳定,负载平均输出电压为250.4 kV,输出脉宽10 ns,重频电压离散程度为11%,负载输出功率为0.55 GW。与变压器油PFL相比,在尺寸保持不变的情况下蓖麻油PFL输出功率基本相同,脉宽提高40%,实现了装置的小型化。更多还原

【Abstract】 The insulating property of dielectric plays an important role in the performance of pulsed power generators. In this thesis, the microsecond pulse insulating properties of castor oil are studied, under different electrode conditions, pulse repetition rates and the hydrostatic pressures. The application of castor oil in a Tesla pulse generator system is analyzed. The detailed work includes the followings:1. Design and simulation of a breakdown test system for castor oilA test cell is designed, in which the electrode gap can be fine-tuned, with the precision of 0.01 mm. There are voltage and current sensors in the cell. Common problems during the experiments, such as the electromagnetic interference, the surface flashover on high-voltage side of cell and maintaining the state of the dielectric between the electrodes, were solved by means of shielding, immersing the cell in insulating oil and circulating the oil respectively. The experiment results agree with the numerical simulation.2. The statistical analysis of the factors affecting the castor oil breakdownWeibull distribution model is selected to analysis the results of castor oil breakdown. Under near uniform fields, the experiment results show breakdown field for castor oil is about 20 kV/mm for DC and 73.5 kV/mm for single pulse condition. Under non-uniform fields castor oil shows higher breakdown field when the needle electrode is positive. The relation of breakdown field with the effective electrode area obeys the 0.27 and 0.18 power law when the needle electrode is positive and negative, respectively. With increasing rep-rate, the breakdown voltage decreases, while the jitter increases; the breakdown electric field of castor oil is increases with the repetitive rate to the -0.12 power. With increasing hydrostatic pressure, the breakdown strength increases with the hydrostatic pressure to the one four power. The impact of hydrostatic pressure on castor oil is greater than that on the deionized water.3. The application of castor oil in the Telsa–type pulse generatorTraditionally transformer oil is used in a Tesla pulse generator. The application of castor oil requires different optimizations. The experiment results show that the output voltage of the load of the single pulse mode is 332.6 kV, and the output pulse width is 10 ns, and the maximum charging voltage of the PFL is 397.8 kV, and the output electric power is 1.08 GW. Under the repetition conditions, the output voltage of the load is 250.4 kV, and the output pulse width is 10 ns, and the data variance is 11%. Compared with the transformer oil PFL, the output pulse width of the castor oil PFL is increased by 40%. This proves that castor oil can be used for compact generators.更多还原