六氟化硫气体质量在线检测和分析系统的设计及应用

气体绝缘设备中的六氟化硫（SF6）会在高压下分解,造成故障,影响电气系统安全。介绍了一种SF6质量在线检测和分析系统的设计方法,以解决电气设备中SF6气体质量难以在线检测和分析的问题。从功能模块划分、电路软硬件设计和系统集成等方面,介绍了检测系统的基本组成。通过检测实验和外场测试,验证了设计的可行性。本研究可以为多种SF6分解产物的检测提供新的手段。在提高现场检测效率的同时,保护工作人员的人身安全,对电气系统的安全运转具有重要意义。     

电气设备绝缘系统局部放电检测技术研究

国内SF6气体绝缘类的电气设备常发生局部放电故障,影响电力系统的安全稳定运行。针对这种情况,文中提出了基于电气设备局部放电的超声波检测技术,对电气设备进行局部放电故障检测与诊断,同时对电力变压器的在线监测进行诊断,最终给出电力变压器的检测图谱。通过使用超声波对SF6气体绝缘类电气设备进行实例验证,结果表明采用超声波技术可以准确地检测出电气设备的电晕放电、悬浮放电等故障。     

SF_6气体成分检测技术在电气设备状态评估中的应用

随着以SF6气体为绝缘介质的电气设备的广泛应用,SF6气体的好坏决定了电力设备的运行安全。在状态检修的推动下,运行电气设备SF6气体成分检测技术也有了很大提高。通过一台110kV LW25-126型SF6断路器缺陷实例测试分析,认为SF6气体成分检测技术能有效地提高对SF6气体绝缘设备状态评估水平。     

氦离子检测器在微量SF6分解产物浓度检测中的应用分析

在SF6电气设备发生故障时,会导致SF6分解,产生气体分解产物,可以利用对SF6分解产物浓度的检测,来诊断SF6电气设备故障。虽然检测SF6分解产物浓度的方法有多种,但要实现对微量SF6分解产物准确检测非常困难,本文阐述氦离子检测器在微量SF6分解产物检测方面的应用。     

LW25-126断路器SF_6气体含有SO_2和H_2S成分的分析研究

随着以SF6气体为绝缘介质的电气设备的广泛应用,SF6气体的好坏决定了电力设备的运行安全。在状态检修的推动下,运行电气设备SF6气体成分检测技术也有了很大提高。在此基础上,结合一台110kVLW25-126型SF6断路器开关返厂解体情况,对其SF6气体中水分超标、H2S气体与SO2气体含量产生和升高的原因进行了分析研究。     

SF6气体绝缘电气设备局部放电超声波检测与应用

本文主要归类并总结SF6气体绝缘类性的电气设备在运行中经常出现的局部放电故障类型,并针对此类设备故障类型提出采用超声波局放带电检测方法来诊断与检测,另外还对电气设备故障诊断采用超声波方法的检测与应用原理进行分析,并通过超声波方法检测SF6气体绝缘电气设备比较典型的故障图谱进行比照分析.同时本文还根据实例来探讨超声波检测SF6气体绝缘电气设备局部放电情况,而实际应用结果证明SF6绝缘电气设备采用超声波检测局部放电情况具有较高的准确性与灵敏度,可以精准的检测出自由金属颗粒、悬浮放电以及电晕放电等缺陷问题,该种检测方法多在带电检测方面、交接试验方面以及电气设备出厂试验方面具有较高的应用前景与使用价值.     

集中式红外SF6气体检测装置及其测量模型

本文提出了一种集中式红外SF6气体检测装置,该装置采用定时循环轮流选通的方式实现2路以上的变电站现场监测点气体采样检测,并采用了单光源双波长光路结构的红外SF6气体采样检测气室。因此有效地降低了制造、安装、调试、维护成本。通过求取每路红外探测信号在光源周期性开关两种状态下的差值和求取这两个差值的比值,降低了温度信号、背景光信号、光源波动等因素的影响。然后在朗伯-比尔定律的基础上,用求取的比值推导求得该检测装置的线性测量模型,最后采用最小二乘法对测量模型进行了标定,从而提高了SF6气体浓度测量的准确性和稳定性。     

变电站SF6泄漏在线监测技术的研究

SF6气体是变电站当中运用较为频繁的气体,一旦发生泄漏,对工作人员以及设备运行都具有较大的危害,因此需要使用在线监测技术对其进行监测。文中简要分析了SF6气体的特性,介绍了部分测量SF6气体的方式,并从激光监测、风机控制等方面分析了SF6泄漏在线监测技术,以期确保SF6气体不会出现泄漏现象,从而保证变电站的安全。     

高压变电站室内SF_6浓度的红外激光吸收检测方法研究

为了实现高压变电站室内SF6气体浓度的精确实时检测,对红外激光吸收方法用于SF6检测进行了研究和分析.根据SF6气体在红外波段(10.55 μm)的强吸收特性,研究了在该波段下SF6吸收特性和其浓度之间的关系,并得出了二者之间的关系曲线.该方法为高压变电站室内SF6气体的定量检测提供了理论基础.     

美国大通研发出专用探测六氟化硫气体激光器——LF6

六氟化硫（SF6）气体以其优异的绝缘和灭弧性能,在电力系统作为良好的气体绝缘体中获得了广泛的应用,遍布了整个变输电系统的各个角落,是重要的绝缘和灭弧介质。据有关资料介绍,现在国外主要的电力设备生产厂商已将245kV及以上高电压和超高电压电气产品全部转向了生产SF6气体绝缘电气设备或装置方面。     

A preliminary study of SF6 based inductively coupled plasma etching techniques for beta gallium trioxide thin film

Beta phase Gallium trioxide (β-Ga₂O₃) thin film was grown by metal organic chemical vapor deposition technology. Mixture gases of SF₆ and Ar were used for dry etching of β-Ga₂O₃ thin film by inductively coupled plasma (ICP). The effect of SF₆/Ar (etching gas) ratio on etch rate and film etching damage was studied. The etching rate and surface roughness were measured using F20-UN thin film analyzer and atomic force microscopy showing that the etching rate in the range between 30 nm/min and 35 nm/min with an improved surface roughness was obtained when the reactive mixed gas of SF₆/Ar was used. The analysis of X-ray diffraction and transmission spectra further confirmed the non-destructive crystal quality. This work demonstrates that the properly proportioned mixture gases of SF₆/Ar is suitable for the dry etching of β-Ga₂O₃ thin film by ICP and can serve as a guide for future β-Ga₂O₃ device processing.     

Rapidly Modulated Wide-Spectrum Infrared Source Made of Super Aligned Carbon Nanotube Film for Greenhouse Gas Monitoring

Non-dispersive infrared (NDIR) gas monitoring has advantages of environment stability, convenient operation and maintenance, wide detection range, and multi-gas-detection capability. However, the conventional IR sources for NDIR gas monitoring, such as miniature lamps, microelectromechanical system (MEMS) light sources, and light-emitting diodes (LEDs), can only work at narrow modulation frequency and spectral range, or require complicated design and fabrication, because of the constraint of materials and work principle. These issues cause low data acquisition rate, poor anti-interference ability and limited gas compatibility to NDIR. Here, the super-aligned carbon nanotube (SACNT) film is developed as an IR source in NDIR gas monitoring system. It has a wide spectral range (0.2–334 µm), a facile fabrication method, and can work up to a high frequency ≈150 kHz. A mechanical-chopper-free and wide-concentration-range monitoring equipment for CO₂ and CH₄ greenhouse gases is demonstrated with SACNT film IR source. The concentration ranges for CO₂ and CH₄ investigated in this paper are 0.0195–20.10% (v/v) and 0.10–17.11% (v/v), respectively. It can be easily applied to monitor other kinds of gases as well.     

SOI planar photonic crystal fabrication: Etching through SiO2/Si/SiO2 layer systems using fluorocarbon plasmas

Dry plasma etching of sub-micron structures in a SiO₂/Si/SiO₂ layer system using Cr as a mask was performed in a fluorocarbon plasma. It was determined that the best anisotropy could be achieved in the most electropositive plasma. A gas composition yielding the desired SOI planar photonic crystal structures was optimized from the available process gases, Ar, He, O₂, SF₆, CF₄, c-C₄F₈, CHF₃, using DC bias data sets. Application of the c-C₄F₈/(noble gas) chemistry allowed fabrication of the desired SOI planar photonic crystal. The average etching rates for the pores and ridge waveguide regions were about 71 and 97 nm/min, respectively, while the average SiO₂/Si/SiO₂ to Cr etching selectivity for the ridge waveguide region was about 33:1 in case of the c-C₄F₈/90%Ar plasma with optimized parameters.     

Deep dry etching of borosilicate glass using SF6 and SF6/Ar inductively coupled plasmas

Deep reactive ion etching (DRIE) of borosilicate glass was carried out using SF₆ and SF₆/Ar plasmas in an inductively coupled plasma (ICP) reactor. Electroplated Ni on Cu (≅50 nm)/Cr (≅100 nm)/glass structure using patterned SU-8 photoresist mask with a line spacing of 12-15 μm was used as a hard-mask for plasma etching. Plasma etching of borosilicate glass was performed by varying the various process parameters such as the gas chemistry, the gas flow ratio, the top electrode power, and the dc self-bias voltage (V_dc). In the case of using SF₆ gas only, the profiles of the etched channel showed the undercut below the Ni hard-mask due to a chemical etching and the microtrenching at the bottom of the etched channel. An optimized process using the SF₆ plasmas showed the glass etch rate of ≅750 nm/min. The addition of the Ar gas to the SF₆ gas removed the undercut and microtrenching but decreased the etch rate to ≅540 nm/min. The increasing and decreasing time-dependent etch rates with the etch depth in the SF₆ (200 sccm) and SF₆(60%)/Ar(40%) plasmas, respectively, were ascribed to the different ion-to-neutral flux ratios leading to the different etch process regime.     

Effect of a surface pre-treatment on graphene growth using a SiC substrate

This study reports surface pre-treatment techniques for the formation of a high-quality graphene layer on a SiC surface. It is demonstrated that silicon passivation of SiC surface using a silane flow and subsequent sacrificial oxidation can significantly improve the surface condition of a graphene layer on SiC by ensuring much fewer carbon dumps and wrinkles, reducing the electrical resistance, and providing smoother surface roughness and a larger domain size. The effect of in situ cleaning by a SF₆ treatment before graphitization was also studied. It was found that in situ cleaning using SF₆ gas can be a simple and effective means of improving the quality of a graphene layer grown on SiC. The results of this study suggest that a surface treatment before graphitization is the key to synthesize high-quality epitaxial graphene layer.     

添加气体对TE N2激光器输出的影响

本文给出了在纯N2中添加SF6和He气对TEN2激光器3371Å输出影响的实验结果。实验结果表明,在纯N2中添加少量SF6,可使激光输出增加一倍,而添加2～3倍He气,可提高输出功率30%～7倍。本文研究艺了添加He气对混合气体电子温度、电子密度和电子能量分布的影响,从而合理地解释了加He气可以提高输出功率这一实验结果。     

Effects of Ar and O2 additives on photopatternable sol-gel etching in an SF6-based plasma for planar lightwave circuit fabrication

We present a novel study of the interaction of SF₆-based plasmas with sol-gel materials in a parallel plate reactive ion etching (RIE) system. The purpose of these experiments was to obtain quantitative measures and optimisation of the RIE parameters, which can be used in the microfabrication of planar lightwave circuit (PLC) devices. The sulfur hexafluoride chemistry is chosen due to its excellent etching properties of SiO₂, which is one of the components of the photopatternable sol-gel materials and is not present in typical photoresist materials. Fast process etching rate and good selectivity is achieved by varying SF₆ flow and power delivered to the electrodes. The study also reveals a marginal influence of oxygen and argon flow on the character of the sol-gel etching. The experimental data obtained can be used as a reference for any sol-gel devices fabricated using widely available RIE reactors.     

Comparison of F2 plasma chemistries for deep etching of SiC

A number of F₂-based plasma chemistries (NF₃, SF₆, PF₅, and BF₃) were investigated for high rate etching of SiC. The most advantageous of these is SF₆, based on the high rate (0.6 μm·min⁻¹) it achieves and its relatively low cost compared to NF₃. The changes in electrical properties of the near-surface region are relatively minor when the incident ion energy is kept below approximately 75 eV. At a process pressure of 5 mtorr, the SiC etch rate falls-off by ∼15% in 30 μm diameter via holes compared to larger diameter holes (>60 μm diameter) or open areas on the mask. We also measured the effect of exposed SiC area on the etch rate of the material.     

基于非分散红外法的二氧化碳浓度检测综述

二氧化碳(CO₂)是温室气体的重要组分之一,实时检测其浓度变化对缓解温室效应等方面具有非常重要的意义。非分散红外(Non-dispersion infrared, NDIR)法具有稳定性好、响应速度快、测量范围宽等优点,广泛应用于便携式气体检测等领域。首先分析了NDIR法应用在CO₂检测领域的优点,并对NDIR检测原理进行了简单的概述。然后对NDIR气体分析仪的基本结构进行了详细阐述,并对测量系统的经典气体标定方法进行了综述。最后综合分析了NDIR的特点,并展望了未来的发展趋势。     

Abnormal metal oxide formation induced by residual charging in plasma etch process

Electron cyclotron resonance plasma with SF₆ and Cl₂ gas mixture were used for tungsten plug etch-back processes. The properties of electric contacts between tungsten plugs and Al/Ti/TiN interconnect lines, fabricated by this etching process, have been studied. Particles and abnormal oxide layers at the plug/line interfaces have been found to be the main factor to cause deterioration of the electric contacts. Mechanisms for particle transportation and metal oxide formation have been proposed. The phenomenon was attributed to the residual charging effect, which occurred immediately after the plasma power being turned off. A technique to prevent the residual charging induced tungsten oxide growth has been developed and applied in industrial fabrication lines.