Excess Heat Triggered by Different Current in a D/Pd Gas-Loading System

In order to study the relationship between the triggering current, deuterium pressure and the excess heat, a series of experiments were made in a D/Pd gas-loading system. By comparing the system constants （k = AT//kP） in both nitrogen and deuterium atmosphere we found an optimum current （8 A） and a deuterium pressure （9 x 104 Pa） in which the system could release a maximum excess power （more than 80 W）. The reproducibility was 16/16 and the excess energy released in the longest experiment was about 300 MJ within 40 days, which was corresponding to 104 eV for each palladium atom. Analysis of the palladium surface with a SEM （scanning electron microscopy） and an EDS （energy dispersive spectrometer） revealed that some new surface topographical feature with concentrations of unexpected elements （such as Ag, Sn, Pb and Ca） appeared after the current triggering. The results implied that the excess heat might come from a nuclear transmutation.

Emission Current Characteristics of Triggered Device of Vacuum Switch

The characteristics of the triggered vacuum switch （TVS） are obviously influenced by the emission current ie and emission charge of the trigger device. In this paper, an RC charge collector is designed, and the characteristics of emission current ie and collecting charge Qc of the trigger device are studied. The experimental results indicate that the emission current ie which is produced by the initial plasma has both positive and negative components, and the polarity of the emission current ie depends mainly on the polarity of the bias voltage UBias. The emission current ie and collecting charge Qe increase with the increase of the trigger voltage Utr and the bias voltage UBias. The emission efficient r] increases linearly with the increase of the bias voltage UBias. When the gap distance is 15 mm and bias voltage UBias is 160 V and trigger voltage Utr is 2.6 kV, the emission efficiency r/reaches 6%

Testing of Lightning Protective System of a Residential Structure： Comparison of Data Obtained in Rocket-triggered Lightning and Current Surge Generator Experiments

We present a comparison of data obtained during testing of lightning protective system of a residential structure in rocket-triggered lightning experiment at the International Center for Lightning Research and Testing(ICLRT)at Camp Blanding,Florida,and current surge generator experiment at Rzeszow University of Technology in Poland.Three different configurations of LPS were tested in Poland with the dc grounding resistances of the entire system 4.09 Ω(LPS 1a),1.65 Ω(LPS 1b),and 2.88 Ω(LPS 2).For LPS 1a with three ground rods the value of the peak current entering the electrical circuit neutral was about 56% of the injected current peak,and for LPS 1b with two additional ground rods and two 5 m long buried horizontal conductors it was about 16%.For LPS 2 with five ground rods interconnected by a buried loop conductor this ratio was 21%.The current waveshapes in the ground rods differed from the injected current waveshapes and the current waveshapes in other parts of the test system,especially,for poorer-grounding LPS 1a.The surge-generator results are consistent with those of triggered-lightning experiments at Camp Blanding,Florida(DeCarlo et al.,2008 [2]).

基于网侧资源协调的自储能柔性互联配电系统日前-日内优化

为优化储能型智能软开关(E-SOP)、传统网侧调控设备的运行策略,提升高渗透率光伏配电网运行水平,提出了基于网侧资源协调的自储能柔性互联配电系统日前-日内优化模型。首先,提出了“源网荷储”下多种网侧资源协调利用的多时间尺度优化控制架构;其次,在日前阶段构建计及有载调压变压器、无功补偿装置、联络开关、E-SOP和柔性负荷的长时间有功-无功联合优化模型,在日内阶段建立多目标滚动优化模型,并采用线性化方法将模型转换为混合整数线性规划模型;然后,基于KL散度构建源荷不确定性模糊集,给出日前两阶段分布鲁棒优化模型转化过程和基于列与约束生成算法的求解方法;最后,算例仿真验证所提方法的有效性。

火箭触发闪电的回击电流及电场特征分析

2019年夏季在广州开展了火箭引雷试验,成功地触发了14次闪电,总回击(RS)数达74次,平均回击数为5.3次,单次闪电的最大回击数为14次。该文对火箭引雷的回击电流及不同距离电场波形特征进行了分析。回击的间隔时间、峰值电流、10%~90%上升时间、半峰值宽度、1 ms转移电荷和1 ms作用积分的几何平均值分别为38.45 ms、12.38 kA、0.25μs、8.31μs、0.68C和2.12×10^(3)A^(2)·s,回击电流的转移电荷量和作用积分量均与回击峰值电流呈幂函数相关性。回击的先导电场强度峰值和回击电场强度峰值会随距离的增大而减小,而电场的10%~90%上升时间和半峰值宽度会随距离的增大而增大。回击电场强度峰值会随距离的增大而呈现出幂函数减小,且峰值电流与不同距离的先导电场强度峰值和回击电场峰值均呈现一定线性相关,距离越大,其线性拟合关系越好。

火箭引雷至架空线路与地面电流对比分析

2018—2019年夏季在广州从化开展了火箭引雷试验,雷击对象分为两种,分别是架空线路和地面。对比了两种引雷情况下各阶段雷电流的电流波形参数的差异,发现引雷至地面情况下初始阶段的最大电流、平均电流、转移电荷、作用积分分别是引雷至架空线路情况下的2.8、2.4、2.0、5.3倍。引雷至地面情况下回击的上升时间几何均值为0.25μs,小于引雷至线路情况下的0.60μs,而对于电流峰值等其他回击波形参数而言,差异不明显。M分量与初始连续电流脉冲类似,引雷至线路情况下的电流峰值、转移电荷、连续电流水平均小于引雷至地面情况下的。基于诺顿电流源等效电路模型分析两种引雷情况下雷电流不同阶段存在差异的原因,可能是雷电在不同电流阶段时其通道等效阻抗不一样所导致的。

混合型限流熔断器触发装置用电流互感器铁芯结构设计

针对短路电流保护装置的电流测控单元因电子元器件失效或电源掉电而导致保护装置拒动的问题,提出了一种无源电磁式电流互感器,分析了触发装置的工作原理,根据铁芯材料的磁化特性曲线,确定了互感器有效工作区间内铁芯的最大磁感应强度。针对铁芯在大电流条件下磁通容易饱和的问题,通过仿真分析了气隙分布对互感器内磁感应强度的影响。设计出在短路电流峰值为15 kA时仍可有效工作的电磁式电流互感器铁芯结构,三维瞬态电磁场仿真显示短路电流上升率为20 A/μs、二次绕组匝数为30匝时,铁芯二次绕组侧输出电压不小于14 V。最后设计制作了采用无源电磁式电流互感器作为触发装置的混合型限流熔断器工程样机,并进行了短路电流检测实验,实验结果与仿真基本一致,证明了铁芯设计的准确性和有效性。

触发闪电环境下地网冲击接地电阻特征分析

基于触发闪电技术,研究了2019年夏季8次触发闪电44次回击、5次初始连续电流脉冲(ICCP)和24次M分量对冲击接地电阻的影响,探索了冲击接地电阻随雷电流注入的动态变化规律。结果发现:闪电放电ICCP、M分量和回击过程冲击接地电阻均小于工频接地电阻,ICCP和叠加在回击回落之后连续电流上的M分量冲击接地电阻略大于回击过程,平均值分别为11.2Ω和10.8Ω。叠加在回击下降沿上的M分量冲击接地电阻平均值7.8Ω,明显小于回击过程,最小值可达2.4Ω。ICCP和M分量冲击接地电阻随电流增加而减小,回击过程与电流峰值没有明显的相关性。叠加在回击下降沿上的M分量冲击接地电阻随雷电流峰值、背景电流值的增加呈指数衰减关系,还与之前回击电流峰值成一定的反比例关系。随着闪电回击电流的注入,冲击接地电阻呈现动态变化过程,小电流在回击峰值下降后出现一个缓慢增长的过程,大电流在回击峰值下降后出现一个快速下降的过程。闪电不同物理过程火花和电感效应的作用是不同的,两者共同作用决定了土壤的电离程度,从而决定了冲击接地电阻的大小和变化。

一起励磁涌流闭锁导致的配电自动化开关异常动作案例分析

立足于当前云南电网配电自动化实用化背景,结合系统内一起配电自动化开关异常动作案例,针对配电自动化开关励磁涌流闭锁功能错误触发开展分析并给出优化建议。首先,介绍了线路参数及保护配置情况,奠定后续分析基础。之后,基于SOE信息复现开关动作过程,明确开关异常动作情况。最后,结合故障录波信息阐述配电自动化开关异动原因,并给出优化建议。

混合直流系统中直流侧故障暂态电流的解析表达与故障特性的研究

由基于线性换流器高压直流输电系统(LCC-HVDC)和基于电压源换流器高压直流输电系统(VSC-HVDC)共同构成的混合直流输电系统,其故障特性与传统直流输电系统不同。针对此问题,对混合直流输电系统中直流侧故障暂态电流特性进行了研究。首先建立了送端电网采用LCC型换流站、受端电网采用VSC型换流站的两端混合直流输电系统,利用拉普拉斯变换定理推导了直流侧故障时的等效电路,解析了LCC侧和VSC侧直流故障电流简易表达式。其次,在简易表达式的基础上,充分考虑送端LCC侧换流站的触发角动态变化过程和受端VSC侧换流站交流电流的馈入,进一步解析了两侧精确的故障电流表达式。然后,从故障电流幅值、谐波等方面对比分析了三种高压直流系统中直流侧故障电流的变化特征。最后,通过MATLAB/Simulink仿真验证了所提故障电流解析表达式的正确性。

Experimental Study of Electron Emission Characteristics of a Surface Flashover Trigger in a Low Pressure Environment

Characteristics of electron emission induced by a surface flashover trigger device in a low-pressure trigger switch were investigated. A test method to measure the emitted charges from the trigger device was developed, and the factors affecting the emitted charges were analyzed. The results indicated that the major emitted charges from the trigger device were induced by surface plasma generated by surface flashover occurring on the trigger dielectric material. The emitted charges and the peak emission current increased linearly with the change in the trigger voltage and bias voltage. The emitted charges collected from the anode were affected by the gap distance. However, the emitted charges were less affected by the anode diameter. Furthermore, the emitted charges and the peak emission current decreased rapidly with the increase in gas pressure in a range from 0 Pa to 100 Pa, and then remained stable or changed slightly when the increase in gas pressure up to 2400 Pa.

A Novel Crowbar Impulse Current Circuit for Testing the Switch-Type SPD

A crowbar impulse current circuit for testing the switch-type surge protective device （SPD） is presented. The crowbar circuit consists of a computer control circuit, a trigger voltage pulse generator, a main discharging switch, and a crowbar pseudospark switch. The active trigger technology was studied in the crowbar impulse current circuit. The circuit monitors the main discharging current and generates a trigger signal at a proper time for the crowbar pseudospark switch operation. The trigger characteristics of the main discharge switch and the crowbar pseu- dospark switch were investigated. By monitoring the preset applied capacitor voltage, the gap distance of the main discharging switch could be adjusted to ensure a discharging delay time less than 2 μs. Equipped with a surface ttashover trigger device made of high relative perimittivity dielectric material BaTiO3 （εr = 3460）, the discharge delay time of the crowbar pseudospark switch is less than 85 ns, and the minimum operating voltage is less than 1% of its self-breakdown voltage. With a storage capacitor of 9 μF , an inductor of 18 μH and a crowbar pseudospark switch, a load of 30 mΩ and an applied capacitor voltage of 40 kV, an impulse current waveform of maximum 25 kA was generated with a rise time and time to half peak value of 17.2 μs and 336μs respectively.

基于人工引雷数据的闪电探测效率及精度评估

利用在山东滨州沾化区人工引雷实验得到的2017-2020年30次闪电数据,对比分析ADTD闪电定位系统在人工引雷场地及其相似地区的定位效率、定位精度及电流峰值偏差。结果表明ADTD对人工引雷触发闪电事件定位效率为60%(即18/30),回击闪电定位效率为88.89%(即8/9),回击过程定位效率34.48%(10/29),ICC闪电定位效率47.62%(10/21)。定位精度31.724 km,负地闪定位精度高于正地闪,2站以上定位精度高于2站定位。电流峰值偏差36.38%。

Analysis of the Spectral Characteristics of Triggered Lightning

The spectra with wavelength range of 390 nm to 660 nm of triggered lightning were observed in Guangdong Area using a slitless spectrograph. The characteristics of the lightning spectra during the initial continuous current and return strokes were analyzed, and the differences between the metal section and air section of the lightning channel were compared. The results showed that the metal spectra were contained in the metal section during the initial continuous current. As for the lightning channel of the return strokes, the line spectra for both the metal section and the air section were identical;neither of the two sections contained the metal spectra, but the relative intensity of its emission spectrum was different. Owing to different radiation mechanisms, the spectral structures and luminance of the two sections were not the same. Combined with the current data, it was found that there was a good positive correlation between the total spectral strength and the transferred charge. The total intensity of the lightning channel spectrum increased with the height of the channel, indicating that the radiation sequence of the lightning channel was different. High temporal resolution observations showed that the spectral line duration could be divided into three categories, in which the lines with higher excitation energy appear first and decay rapidly, while those with lower excitation energy appear later but last longer.

Investigation on 10/350 Crowbar Pulse Current Circuit

Structure of main air discharging switch and a crowbar TVS （triggered vacuum switch） are designed and their triggering characteristics are investigated. The experimental results showed that for TVS the operating voltage range is from 1.3 kV to 120 kV, its maximum delay time is 400 ns and its jitter is 4-10 ns. Based on these results the crowbar 10/350μs （i.e., with a front time of 10μs and a duration of 350 μs） pulse current circuit and its controlling circuit are designed. With a 10μF stored capacitor C and a 6 μF waveform forming induction, a pulse current is generated with a maximum of 100 kA, front time of 10 ns and duration of 350μs. This pulse waveform can be used for testing SPD （surge protective devices）.

换流变压器直流偏磁对油箱涡流损耗的影响

换流变压器直流偏磁状态下油箱涡流损耗会大幅增加,导致变压器温度升高,威胁其安全稳定运行,因此快速评估直流偏磁下油箱涡流损耗的大小就显得十分必要。该文首先分析了换流变压器在额定和空载直流偏磁状态下油箱表面漏磁场的分布特点。再结合实际换流变压器非线性负载电流和励磁电流波形,得到了不同换流器触发角和直流电流下油箱涡流损耗的变化规律。并在IEC/IEEE 60076-57-129标准的基础上,给出了换流变压器直流偏磁状态下油箱涡流损耗的计算公式。针对一台800 kV单相四柱式换流变压器,利用场路耦合法进行油箱涡流损耗有限元计算。通过对损耗仿真数值以及油箱表面磁通密度和涡流损耗分布的分析,验证了理论分析的正确性,并获得了不同工况下,计算公式中的损耗占比值。利用不同属性的线性负载替代换流器触发角的变化,对两台单相四柱式380 V交流变压器进行了直流偏磁实验,进一步验证了理论分析的正确性。

火箭引雷至架空线路与地面近距离磁场对比分析

2019年夏季在广东开展了引雷至架空线路和引雷至地面两种工况下的人工引雷试验。分别对两种不同试验工况雷电产生的不同距离磁场波形数据进行测量。分析了不同距离的总磁感应强度峰值、先导磁感应强度峰值、回击磁感应强度峰值、10%~90%上升时间和半宽时间等磁场波形参数,对比了两种引雷情况下不同距离回击磁场波形参数的差异。结果表明,引雷至架空线路情况下磁场幅值更低,约低12%,引雷至线路情况下磁场10%~90%上升时间和半宽时间更大,分别高出约60%和70%。总磁感应强度峰值随着距离的增大呈幂函数衰减,引雷至地面情况下总磁感应强度峰值衰减得更快。回击磁感应强度峰值同样呈现出相似的规律,而先导磁感应强度峰值与距离之间不存在明显单调变化的关系。两种引雷情况下,不同距离的总磁感应强度峰值与回击电流峰值之间均存在线性关系。

人工引雷至架空线路与地面雷电流峰值估算比较

基于2018—2019年在广州从化进行的引雷至架空线路和引雷至地面两种火箭引雷试验,分析对比了两种引雷情况下在试验现场测得的回击实测电流峰值以及由雷电定位系统提供的回击估算电流峰值和回击远电场峰值,评估了两种引雷情况下雷电定位系统的电流估算情况。引雷至地面(线路)情况下87(70)次回击实测电流峰值的几何平均值是13.4(16.4)kA。相对于引雷至地面的回击,引雷至线路情况下回击电流峰值估算误差整体更偏向纵轴的负轴,这可能是因为电流峰值相同的回击,引雷至线路时产生的远电场峰值比引雷至地面时约低14%。

基于在线监测的雷电流识别方法及其应用

对于输电线路的雷击过电压在线监测装置,快速准确地识别雷电流信号至关重要,目前不论是硬件触发还是软件触发都存在误触发和漏触发等触发问题,而且目前的监测系统在经济性和便捷性方面存在明显弊端。本文提出一种基于嵌入式的雷击在线监测系统,可以实现对输电线路高效便捷的实时监测,极大的提高雷击监测装置的便捷性和经济性。同时提出先检测后识别的触发算法准确识别雷击电流暂态信号,首先通过幅值差的方法快速检测雷电流信号(不良数据),然后通过周期作差的方法准确识别不良数据,通过分析实验,证明该方法可以减少监测系统的误触发和漏触发次数。并且通过实验室测试,证明该监测系统的采集精度为98.49%,满足实时监测的需求,为输电线路在线监测提供一种经济便捷的监测系统。