共查询到19条相似文献,搜索用时 187 毫秒
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介绍了电阻分压器型负载的结构、分压原理和设计方法,分析了高频作用下趋肤效应对负载阻值的影响,计算了负载和真空腔内的电场强度分布以及负载的等效电感和等效电容,利用Pspice程序模拟了回路参数对输出信号的影响。对负载的分压比进行了标定,标定结果为7.59×10-5。为避免闪络现象的发生,设计加工接地金属套筒,用来降低负载阴极三结合点处的电场强度。负载工作电压幅值428 kV,电流幅值9.48 kA,工作阻抗45 Ω,电压和电流波形与设计值符合得较好,满足设计要求。 相似文献
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介绍了一种用于脉冲功率装置真空绝缘子的环氧树脂基复合材料的研制机理、制备过程和典型性能。初步测试结果表明,添加一定量的水合氧化铝颗粒可以使环氧树脂材料的表面电阻率由5×1016 Ω降低为6×1011 Ω,这一特性有利于释放由于沿面闪络等原因沉积在真空绝缘子表面的电荷,从而使材料在脉冲电压下的沿面闪络电压有所提高,实验得到在上升沿400 ns的脉冲电压作用下, 沿面闪络电压可从17 kV 提高到 28 kV。 相似文献
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为了满足“神光-Ⅲ”原型装置能源系统的需要,桂林金属膜电容器厂研制成功一种高比能脉冲电容器,其尺寸为295 mm×138 mm×730(830) mm,额定电压25 kV,额定电容及偏差为55 μF,0~5 %,损耗角正切值(2.5 kV,50 Hz)小于 0.1%,比能达0.56 J/cm3 。对该型电容器进行性能测试,所得电容偏差都在2%~5%范围,损失角正切值小于0.05%;极间耐压试验全部通过,极-地耐压试验全部通过。寿命试验中,放电电流5 kA,1×104次充放电后,电容量下降1.8%。该型电容器目前已投入运行,工作情况良好。 相似文献
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介绍了一种基于空芯变压器的三谐振高压脉冲变压器。通过对三谐振脉冲变压器无损等效电路的理论分析,给出了在回路本征频率为1∶2∶3时,电路各参数的关系及输出电压解析表达式,由此可知在此条件下变压器次级高压绕组上的最大电压与负载电容上最大电压比为0.36∶1。根据理论结果,设计了一组参数进行了电路模拟,证明了理论分析结果的正确性,可用于三谐振脉冲变压器的设计。并模拟了变压器耦合系数、调谐电感、调谐电容、初级电容及负载电容等参数变化对装置输出电压及能量传输效率的影响。由模拟结果可知,调谐电感和调谐电容在-10%~10%范围,初级电容在0~10%范围以及负载电容在-10%~0范围内变化对装置的性能影响不大,该变压器较容易实现工程化。 相似文献
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研制了一台300 kV/3 ns快前沿脉冲电压源。为了得到快的前沿,设计了低电感的峰化电容和输出开关。其中峰化电容采用3个薄膜电容同轴串联设计,结构紧凑,分布电感小,电极端部的气隙结构使其能承受更高的脉冲高压,实验证明这种结构的峰化电容能承受前沿17 ns、峰值大于300 kV的脉冲高压。输出开关采用高气压小间隙SF6开关,最高工作气压1 MPa,具有较小的分布电感和火花通道电感。经实验调试,由该峰化电容和输出开关组成的峰化回路在500 kV Marx发生器的驱动下,在150 Ω负载上可得到峰值电压大于300 kV、前沿小于3 ns的脉冲电压输出。 相似文献
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针对高功率激光系统中信噪比低的问题,基于描述超短脉冲传输的非线性薛定谔方程进行数值模拟,研究了高阶群速度色散、光谱调制及自相位调制对脉冲信噪比的影响;新建立了用于分析光栅平整度对脉冲信噪比的影响的物理模型并进行了相应的模拟,分析了光栅的质量要求或补偿精度。研究表明:对于100 fs的高斯脉冲,要保证信噪比达到108,应将三阶色散量限制在4.8×105 fs3以下,B积分的值应小于0.2,光谱的调制幅度应小于10-4,光栅平整度应优于λ/100。 相似文献
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对高功率超宽谱辐射源的参数进行了理论分析设计,对高压电源、脉冲产生、阻抗变换及传输线、天线等各部分的具体参数进行了分解匹配。根据理论计算结果,设计了一套高功率超宽谱辐射装置并进行了实验研究,对输出功率、辐射效率等进行了调试,在2.7 Ω负载上获得脉冲输出功率超过30 GW、脉冲宽度1.6 ns,通过超宽谱Cassegrain双反射面天线辐射,等效辐射峰值功率超过2×1012 W,辐射因子超过8 MV,H面与E面3 dB宽度分别为2.35°和2.27°。 相似文献
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通过自洽求解一维Poisson-Schrdinger方程,模拟了AlGaN/GaN高电子迁移率晶体管在工作时等效外电场对AlGaN/GaN异质结沟道处二维电子气(2DEG)浓度的影响.分析了逆压电极化效应的作用,从正-逆压电极化现象出发,提出了逆压电极化模型.计算结果显示:逆压电极化明显影响2DEG性质,当Al组分x=0.3,AlGaN层厚度为20 nm时,不考虑逆压电极化,2DEG浓度为1.53×1013cm-2;当等效外电压分别为10和15V
关键词:
AlGaN/GaN高电子迁移率晶体管
Poisson-Schrdinger方程
逆压电极化模型
电流崩塌 相似文献
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We have studied the differential capacitance of self-assembly hybrid organic/inorganic quantum dot (QD) light-emitting devices
(QD-OLEDs) at room temperature in the frequency range of 1×103 to 1×106 Hz. Self-assembly CdSe/ZnS QDs monolayer was used to fabricate trilayer hybrid QD-OLEDs on indium tin oxide coated glass
substrates. We observed negative differential capacitance (NDC) in both OLED and QD-OLEDs for the first time in the intermediate
frequency range of 5×103 to 5×105 Hz. The onset and frequency range of NDC are strongly depended on the applied bias voltage. This behavior is described by
a mathematical model. The simulated results showed that the NDC was due to the time-dependent transient current from the QDs
and organic/metal interfacial states in the device. The probable mechanisms of NDC in organic devices are discussed. 相似文献
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Temporal parameters of the current pulses generated by a Gunn diode operating in domain mode in relation to the supply voltage and load resistance are numerically simulated. The results of the numerical and analytical studies are compared. The validity range of the analytical formulas is ascertained in detail. In the context of the considered model, the minimum pulse duration and the time of domain formation are obtained at zero load and for a supply voltage exceeding the critical value by a factor of 1.25. 相似文献
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Analysis of each branch current of serial solar cells by using an equivalent circuit model
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In this paper,based on the equivalent single diode circuit model of the solar cell,an equivalent circuit diagram for two serial solar cells is drawn.Its equations of current and voltage are derived from Kirchhoff’s current and voltage law.First,parameters are obtained from the I–V(current–voltage)curves for typical monocrystalline silicon solar cells(125 mm×125 mm).Then,by regarding photo-generated current,shunt resistance,serial resistance of the first solar cell,and resistance load as the variables.The properties of shunt currents(Ish1and Ish2),diode currents(ID1and ID2),and load current(IL)for the whole two serial solar cells are numerically analyzed in these four cases for the first time,and the corresponding physical explanations are made.We find that these parameters have different influences on the internal currents of solar cells.Our results will provide a reference for developing higher efficiency solar cell module and contribute to the better understanding of the reason of efficiency loss of solar cell module. 相似文献
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Fabrication and characterization of 4H—SiC bipolar junction transistor with double base epilayer
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In this paper we report on a novel structure of a 4H-SiC bipolar junction transistor with a double base epilayer that is continuously grown.The measured dc common-emitter current gain is 16.8 at IC = 28.6 mA(J C = 183.4 A/cm2),and it increases with the collector current density increasing.The specific on-state resistance(Rsp-on) is32.3mΩ·cm 2 and the open-base breakdown voltage reaches 410 V.The emitter N-type specific contact resistance and N + emitter layer sheet resistance are 1.7×10-3 Ω·cm2 and 150 /,respectively. 相似文献
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