高压真空接触器控制原理分析及优化设计

针对目前高压真空接触器在控制方面出现的问题,对接触器与断路器在工作原理和控制原理上的区别进行了详细论述,并就行业上通用的一种接触器控制原理所存在的问题进行了分析论证,并提出改进设计.     

提高办理电气工作票效率的探讨

找出影响变电站值班员办理工作票的因素,并根据各种因素制定相应的措施,以提高变电站值班员办理工作票的速度,达到提高工作效率的目的,实现设备和电网安全稳定运行的目标。     

Determination of gas pressure in vacuum interrupter based on partial discharge

Partial discharge characteristics in air under a low vacuum region were studied to develop a diagnosis technique to determine the gas pressure in a vacuum interrupter. The pressures were set at from 1.3 Pa to 2.6 kPa in order to simulate the leakage of gas into the vacuum interrupter. The structure of the vacuum interrupter, the measurement and the circuit construction for the experimental setup were described. The measurement of partial discharge occurring inside the vacuum interrupter was performed with a current transformer, intensified charge coupled device (1CCD) camera and photomultiplier tube. The measurement of partial discharge light intensity with a photomultiplier tube was more sensitive compared with that measured with a current transformer. From this result, an attempt has been made to distinguish the pressure below and above 260 Pa on the basis of the rise time and peak intensity of discharge light pulses. A relatively longer rise time (2 mus) with a smaller magnitude (less than 0.5 mA) was attributed to a Townsend-like discharge at pressures below 260 Pa, while a sharper rise time ~(10-100 ns) with a larger magnitude (greater than 1 mA) was characterized as a streamer-like discharge above 260 Pa. In addition, the estimation of gas pressure in a vacuum interrupter was made based on phase-resolved discharge characteristics utilizing an artificial neural network.     

电气设备中SF6气体泄漏的原因分析

从电气设备的加工、安装和使用各环节对SF6气体泄漏特点、原因进行分析,提出了应对SF6气体泄漏的预防措施。     

Light emission in XLPE subjected to HV in high vacuum andpressurized gas

The spectral and spatial resolution of electroluminescence, the light emitted from polymeric insulation subjected to high electric field, is studied in a test cell pressurized to 215 kPa with ultra high purity nitrogen gas. The paper also describes light emission from crosslinked polyethylene (XLPE) subjected to HV in an ultra high vacuum test cell. It is shown that the characteristics of light emitted from XLPE in the evacuated test cell are quite different from the light emitted when the test cell is pressurized. The mechanisms responsible for light emission under high vacuum condition are described and it is suggested that care should be taken when interpreting the light detected from polymeric insulation subjected to high electric fields     

Methods for estimation of the vacuum status in vacuum circuitbreakers

In this paper several methods are described for the estimation of the pressure inside vacuum interrupters which have been in operation for many years. The methods are applicable without demounting the interrupters and use only electrical measuring techniques. According to these methods the vacuum circuit breakers are subjected to synthetic circuits, switch-off limited currents, either 10 A dc or 300 A ac. With the 10 A dc method the height of arc voltage spikes are measured and represented in a histogram. The shape of the histogram is discriminative for pressures below or above 10^-2 Pa. Switching tests with currents of 200 to 400 A ac in inductive and capacitive circuits also showed different behavior for internal pressures below or above 10^-1 Pa. A three phase 200 A test device with a 10 kV recovery voltage, fed from a standard 380 V supply, showed similar results     

126kV户外真空断路器灭弧室电场仿真计算

采用有限元软件对126kV户外真空断路器的灭弧室内部电场进行了仿真计算，考虑了灭弧室内部各种屏蔽罩对电场分布的影响，得出了一些有益的结论，为户外真空断路器的设计提供了理论基础。     

光声光谱技术在油浸式电气设备故障气体检测中的应用

光声光谱气体检测技术具有精度高、检测范围宽、不消耗被测气体和载气等优点,适用于油浸式电气设备油中溶解气体的在线监测。对气体光声信号的产生机理进行了理论研究,分析了油中溶解气体的红外光谱特性。基于顶空脱气和光声光谱监测技术,构建了油中溶解气体在线监测平台。结合平台对标准气样和标准油样进行重复性和准确度的测试。采集实际运行的变压器中的油样,与实验室的气相色谱仪进行对比测试,结果都达到或优于电力系统油中溶解气体在线检测的要求,能有效地检测油浸式电器设备油中溶解气体含量。     

Use of gas plasmas to increase breakdown strengths in polycarbonatefilm/foil capacitors

It is shown that the electrical breakdown voltages of polycarbonate film/metal foil capacitors can be increased. This can be achieved by briefly exposing the metal foil in these spirally wound film foil sections to a low-pressure, low-temperature gas plasma. Exposure of tin/lead foil to a 96% CF₄/4% O₂ gas plasma for four min, for example, produced >500% increase in breakdown voltage of sealed polycarbonate capacitors     

A simple and effective design strategy to increase power conversion efficiency of linear charge pumps

This paper introduces a simple design strategy to increase the power efficiency of linear charge pumps. The technique exploits a voltage amplitude of the clock signal lower than the supply voltage to reduce the power conversion losses. The nominal output voltage is maintained unaltered by increasing the number of stages.     

送电线路常用基础优缺点及适用性

分析了架空送电线路常用的几种基础型式在施工难度、工程造价等方面的优缺点,阐述了其对各种地形、地质的适用性,简单论述了各种基础型式在设计、施工方面的注意事项.     

计及冷、热、电联产的气电互联网络最优调度

能源互联网的发展提高了系统的能效、经济性和安全性。储气备用不仅维护了气网自身的安全运行,还能支持燃气轮机出力快速变化,提供电网额外的灵活备用,这对平衡电网中的可再生能源和多能源负荷具有重要意义。此外,气电网络间的高效协调互补,与包括冷、热、电三联产设施在内的多能源应用的运行也有赖于充足的储气备用。为促进气电互联网络安全高效地运行,创新地将储气备用纳入调度优化,提出了一种含有三联产设施的气电互联网络的多目标最优调度模型,并使用NSGAII进行求解。算例分析显示了所提方法的有效性。     

微机综保器在6kV高压电机保护与控制中的应用

介绍了SPAC320C型微机综保器的基本功能和主要特点,分析了SPAC320C型微机综保器保护模块的保护原理,并通过一实例介绍其在6kV高压电机保护与控制中的应用.     

Fundamental experiment and numerical simulation of pre-ionized inert gas plasma MHD electrical power generation

The experiments of pre-ionized inert gas plasma MHD electrical power generation are conducted, and the performance and plasma behavior in the experimental generator are examined through time-dependent r-_ two-dimensional numerical simulation. In the experiment, an enthalpy extraction ratio of 4.01% has been obtained with a disk-shaped MHD generator with radio-frequency pre-ionization. In the numerical simulation, at an assumed inlet electron temperature around 5600 K (inlet ionization degree 0:10 × 10⁻⁴)_6600 K (1:36 × 10⁻⁴), the plasma structure is similar to the non-uniform structure observed in the experiment. An enthalpy extraction ratio around 2_5% matches well with that in the experiment. At a suitable inlet electron temperature of 7000 K (3:15 × 10⁻⁴)_8000 K (1:79 × 10⁻³), although non-uniform plasma structure still occurs, a high enthalpy extraction ratio over 10% is expected.     

Thermodynamic model for electrical tree propagation kinetics in combined electrical and mechanical stresses

In this paper we develop a kinetic model for the growth of electrical tree structures in solid polymeric insulation that allows for combined electrical and mechanical stresses. We present an energy balance analysis during the tree growth process and show the total tree extension driving force is not a material constant due to the existence of a damage process zone around the tree tip and the dissipated heat and the trapped energy remaining in the damage process zone. We derive both the tree growth rate equation and life formula of tree propagation to breakdown, based on the specific tree growth mechanism and the fractal nature of tree structures. We perform electrical tree growth tests in epoxy resin samples with and without mechanical residual stresses, and present results which show that the proposed model can give predicted tree propagation times to failure in good agreement with the experimental data of the tree growth subjected to a combined electrical and mechanical stress     

真空断路器的调整与维护

1.真空断路器的调整真空断路器目前在输配电系统中的投入越来越多,在使用前,4个方面必须要调整和检查。 (1)行程开距的调整:真空断路器的操动机构总行程和真空灭弧室的触头开距随开关的电压等级不同而有所差别,达不到要求的应该进行调整。有2个办法,首先,调节缓冲垫的厚度;其次,调整动导电杆端的可调螺钉。 (2)超行程的调整:一般情况下的超行程是触头开距的15％～40％。调整的方法是动导电杆端可调整螺钉与绝缘拉杆的可调螺钉互相配合调整。     

真空灭弧室真空度测量方法的探讨

通过磁控放电原理的阐述,指出在外激励电源、真空灭弧室的几何尺寸、所用材料一定时,真空灭弧室内的真空度与电离的电荷量有非常准确的对应关系。介绍了采用电离电荷量测量真空灭弧室真空度的方法及在南京地区一年来的现场实测的应用情况。     

扩径导线的分类与扩径方式的选择

扩径导线主要用在特高压线路、高海拔地区、人口密集 的地区。介绍了国内外扩径导线的应用情况和针对“皖电东 送”淮南-上海输变电工程线路研制的2 类扩径导线。通过分 析现有的扩径导线的特点,提出了扩径导线的分类方式：按用 途分为线路用和变电站用2 大类;按结构特点分为大内径铝管 支撑型扩径导线、小内径铝管填充型扩径导线、疏绞型扩径导 线、高密度聚乙烯支撑型扩径导线。在总结研发经验的基础 上,提出了选择扩径方式的原则性意见。     

Investigations on the VUV emissions of Ne-Xe-Cs gas mixturesexcited by an electrical discharge

UV emissions of Ne-Xe-Cs mixtures excited by a pulsed electrical discharge were investigated experimentally as a function of gas pressure and gas composition. For the studied discharge plasmas no fluorescence emissions originating to the radiative decay of the ionic excimer molecule (XeCs)⁺ at 160 nm were observed. Discharge excitation seems to be unsuitable for the generation of this ionic excimer. Previously reported fluorescence emissions due to the radiative transitions in the discharge-excited (XeCs)⁺ molecule could not be confirmed in our experimental conditions. An upper Limit for the unknown rate constant of the formation reaction Xe*+Cs⁺+Ne→Xe⁺Cs+Ne was given