初论介质带电及静电分选技术

本文论述了人们对物质带电、介质带电的认识与进展。除了金属导体（含矿粒）的静电感应（感应起电）、传导带电以外，所有静电现象几乎均源自介质带电。基于静电（电晕、感应及摩擦起电等）机制。对矿料、食品等的静电分选技术，拓展了静电应用科技领域，值得我同仁研究开发之。     

变压器油的静电性能及变压器油流静电试验方法

本介绍了采用“过滤式”带电度测试装置对国产变压器油的带电度及有关静电带电性能进行试验研究的结果，分析了变压器油流带电过程及静电放电特点。此外，初步试验研究苯并三唑对油中静电的抑制作用及其影响，在此基础上，探讨了检测变压器中油流静电的试验方法。     

基于响应面法的多绕组中频变压器绝缘结构优化设计

中频变压器功率密度高、体积小、绕组结构复杂、局部电应力强，变压器设计必须充分考虑电热应力裕量以保证可靠性。本文采用增加静电环和角环的方法对初级绕组端部区域的电场强度进行抑制；采用静电场有限元分析方法计算多绕组变压器的电场强度分布；结合灵敏度分析方法研究静电环和角环各个尺寸参数对电场强度的影响程度，确定最大电场强度的决定性影响因素；利用响应面法构建与电场强度相关的响应面函数，对变压器绝缘结构进行优化。结果表明：以一台50 kW、10 kHz多绕组中频变压器为例，通过上述响应面函数得到静电环和角环的最优尺寸，可以使短时工频耐压试验下的最大电场强度降低15.4%，额定运行工况下的最大电场强度降低17.5%，证明响应面法可应用于多绕组变压器绝缘结构的设计。     

煤矿井下的瓦斯和煤尘

煤矿井下的瓦斯和煤尘天津职业大学董鹤歧摩擦起电的现象在生活中经常遇到，至于电在工业生产中的意义，却使许多人只注意了它的有益之处，而忽略了它所造成的危害。静电火花放电所引起的突发性燃爆，使得厂矿设备遭到破坏，甚至造成人员伤亡，这就是静电的危害。煤炭是重...     

高电压大容量变压器的油流带静电问题

介绍了近年来国内外对大型变压器中油流动产生静电的研究与进展,综述了变压器油中静电产生的机理、测量变压器油流动带静电的仪器装置和技术,讨论了油温、油流速度、油加工工艺、油中水分等影响变压器油流动带静电的主要因素和抑制变压器油流动产生静电的方法。     

BaTiO3掺杂驻极体复合纳米纤维的制备及其在变压器绝缘油先进再生技术中的应用

驻极体效应可提高滤膜对极性杂质的吸附能力,本研究将驻极体技术与静电纺丝工艺相结合,制备了BaTiO3掺杂复合纳米纤维变压器绝缘油滤膜。通过对电纺参数与纤维膜形貌之间关联开展了较为系统的研究,得出制备直径和孔径较小且无串珠PVDF纳米纤维膜的电纺条件。随后进行变压器绝缘油再生实验。结果表明：制备的变压器油滤膜具有可清除极...     

静电除尘器绝缘子的故障分析及改造措施——中国铝业山西分公司煤气分厂技术改造

我国最大的发生炉煤气生产单位——中国铝业山西分公司煤气分厂，共有TG-3M Ⅰ型煤气发生炉22台，其生产出的煤气经洗涤塔洗涤、冷却后，进入静电除尘器进一步除尘，净化后的煤气经加压后供生产和生活使用。其中，除尘器采用的是湿式高压静电除尘器，即在静电除尘器内部形成60KV的高压直流电，煤气中的微小粒子就被吸附到塔内的沉淀极上，然后用水冲走。电源由升压整流变压器经电缆、绝缘穿墙套管、送进静电除尘器内。     

谈粉尘静电现象及其预防

阐述了粉尘静电的起电机理及其防爆措施。     

静电环制作小诀窍

指出了变压器用静电环常规制作方法的不足，介绍了制作静电环的小诀窍。     

蒙皮材料静电起电理论分析及实验验证

飞行器在飞行过程中会因与空间粒子的摩擦等原因在其表面积累大量静电。为了减小静电积累对飞行器及机载设备的影响,对飞行器蒙皮材料与空间粒子的摩擦起电特性进行了研究。首先以固体接触分离起电为基础,推导出了摩擦起电电位的计算公式。计算结果表明:材料静电电位随时间以负指数规律增加并逐步趋近饱和值,该饱和值与材料的性质有关,并与摩擦速度的1.8次幂和接触面积成正比。为验证计算结果,以某飞行器的蒙皮材料为研究对象进行了摩擦起电实验。在连续测试的实验中发现:材料起电电位的饱和值会逐渐降低;不同材料和不同摩擦速度时静电电位饱和值的变化情况证实了计算得到的金属材料摩擦起电电位与材料摩擦系数和接触面积的对应关系。     

Increase of static electrification in an aged oil‐immersed transformer

Increase of static electrification activity and discharge generation was experienced during the service operation of an aged power transformer. The transformer oil had high sulfide and sulfoxide contents and was liable to show high ECT value after aging. However, there was no apparent increase in standard ECT (electrostatic charging tendency) measurement of the insulating oil and, therefore, deterioration of pressboard was suspected as the cause of the increase. The ECT tests with aged oil and pressboard sampled from the aged transformer were insufficient to demonstrate the increase in static electrification for the aged transformer. On the other hand, the results suggested a possibility that increase in static electrification can be caused by adsorption of some deterioration compound in the aged oil to the pressboard. In order to make more effective evaluation to the transformer insulation, potential measurement on the pressboard in the oil duct was carried out. The experimental results demonstrated strong increase of the accumulated charge by the aged pressboard, which suggested effectiveness of potential measurement for the assessment of static electrification in transformers. The device of potential measurement for practical use was designed by reducing the necessary amount of oil sampling. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 167(3): 10–19, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20789     

Relationship between static electrification of transformer oils with turbidity and spectrophotometry measurements

The paper presents the research results on electrostatic charging tendency (ECT) of transformer oil in a spinning disk system. The measurements were performed at different aging severity. Changes in static electrification were related to some classical aging indexes (conductivity, dissipation factor, water content, resistivity, etc.). Fast, inexpensive and reliable laboratory testing procedures developed by ASTM (D 6802 and D 6181) were also used to monitor the decay products as trace impurities. The obtained results show that static electrification currents increase with temperature, oil flow velocity, coating disk material properties and oil’s aging byproducts. The polarity, the amplitude and the time constant of the streaming electrification currents are also affected. This contribution is not only intended to provide a fresh review in this domain of research, but also contains a substantial amount of new material with a view of closing some gaps in the present state of knowledge of transformer oil streaming electrification phenomenon.     

A parametric study of streaming electrification in a full-scalecore-form transformer winding using a network-based model

Streaming electrification remains a problem for large power transformers which require forced-oil cooling. Oil flowing against cellulose insulation surfaces results in the separation of charges from the electrical double layer at the interface. This process can generate hazardous static potentials and volume charge densities in the transformer dielectric system. While streaming electrification has been studied in great detail using small-scale laboratory models, extension of these results to full-scale transformers is rather difficult. This issue has been addressed through the development of a network-based analytical approach which is calibrated against empirical data at the elemental duct level. The model has been utilized to perform a parametric study of streaming electrification in the full-scale high-voltage winding of a core-form transformer. Volume charge densities exiting from each duct in the structure and the local surface potentials are predicted as a function of influent charge, oil volume flow rate, temperature and applied voltage     

Static electrification and partial discharges induced by oil flowin power transformers

This paper presents the study of the major parameters on static electrification, using full-scale shell type transformers (570 MVA, 405 kV and 100 MVA, 500 kV). The consequences of static electrification on the dielectric strength and the conditions of partial discharge occurrence also are studied with oil flow rate up to 5 times the nominal value. It shows that the leakage currents are strongly influenced by temperature, applied voltage and oil flow rate Q. The latter is the most influential parameter. The winding leakage current I varies as Qⁿ , where 1⩽n⩽3. The maximum value of I is observed at room temperature (20°C) when the transformer is energized     

变压器油中局部放电下的油流带电分析

对变压器油漉带电现象进行了研究,分析了油流带电问参数的关系以及影响因素,阐述了油流带电现象产生的原因.     

大型换流变压器油流带电问题的分析

油流带电可能破坏换流变压器的油道绝缘性能,成为威胁超高压变压器甚至影响电网安全、稳定运行的重要因素之一,在特殊的绝缘结构和油冷却方式下,换流变压器中可能存在较多的油流带电问题。通过分析油流带电的产生机理、影响因素、抑制措施和换流变压器的结构特点,研究了换流变压器的油流带电问题。研究表明,降低油速和改善绝缘(特别是油道)设计是减少油流带电问题的最重要措施。开展全电压空载试验等可检验、监测换流变压器的油流带电问题是否严重,此外,向绝缘油中添加电导率调节剂或电荷抑制剂也可降低油流带电的倾向。     

变压器油流带电现象

为了抑制油流带电造成的危害同时最大程度地减少热效应对绝缘的影响,延长变压器的使用寿命,通过对变压器油流带电现象的分析,得出变压器内的绝缘击穿通常发生在上油箱内,因此变压器设计时,应采取有效措施降低上游带电油流对上油箱内局部放电的影响;同时提出应对冷却油泵进行智能控制,使其在流速和温度最佳点运行。在对现有变压器简单油道内油流计算分析的基础上,提出芯式变压器复杂油道内油流带电的计算可通过以下方式实现,即将油道近似等效为简单直管连接而成的管网,然后利用基尔霍夫电流定律和简单直管内的油流带电计算模型求得油道内任意一点的油流带电情况,这为实际变压器油道内的油流带电计算提供了一种新方法。     

变压器油流带电现象及其影响因素分析

分析了变压器油流带电的影响因素,并阐述了变压器油流带电现象的产生机理.     

变压器油流带电数学模型的研究及其应用 第一部分：数学模型的推导

由油流带电引发的变压器事故或故障引起了各国电力部门的广泛关注，许多国家纷纷开展变压器油流带电的研究，大量的油流带电的机理模型也就应运而生。本文在国外学者提出的流动作用机理和电动作用机理两种机理模型的基础上，推导出变压器油流带电的数学模型，与目前存在的几种典型的油流带电计算模型相比，本模型的特点在于它可综合反映起电的流动作用和电动作用，并可基本反映油流流速、油品电导率、外加交流电场强度和系统温度等因素对油流带电的影响。关于本模型的应用实例及与实验的比较见第二部分。