变压器绝缘油中添加金属钝化剂的工程应用

针对某电网公司22台变压器油中金属钝化剂不足的问题,采用自主研发的金属钝化剂添加装置添加金属钝化剂,并通过定期取样检测金属钝化剂含量和腐蚀性硫含量对添加效果进行验证.结果表明:添加金属钝化剂可以有效缓解腐蚀性硫对变压器的腐蚀,并指出了添加金属钝化剂过程中防止漏油、防止空气混入、控制注入流量及防止污染物进入等关键性问题.     

变压器绝缘油中金属钝化剂的降解产气机制研究

相关研究表明,向油浸式电力变压器中添加金属钝化剂会导致油中溶解气体生成异常,为更好地了解油纸绝缘中苯并三氮唑类钝化剂的降解产气过程,指导绝缘油变压器故障诊断,选用在油浸式电力变压器中广泛使用的金属钝化剂——苯并三氮唑(Benzotriazole,BTA),在分子模拟环境下构建BTA分子模拟体系,基于ReaxFF反应力场对2000～3000K下BTA分子模拟体系的热解过程进行分子动力学模拟,并进一步结合BTA的热重试验分析与油纸绝缘中BTA在热场作用下的试验研究,从微观与宏观两个层面综合分析油纸绝缘中BTA的降解产气机制。仿真结果表明,BTA热解会生成小分子烃类自由基、小分子烃类化合物以及H·、N·等自由基,最终形成低分子烃类气体与H₂、N₂、NH₃等无机产物。宏观试验结果表明,BTA随温度的升高不断发生热解,油中BTA的加入会导致油中溶解气体生成异常,其中H₂、CO₂、CO含量明显上升,但总烃含量反而下降。结合微观分子模拟仿真分析、油中溶解气体及绝缘油相关理化参量的宏观变化规律...     

变压器绝缘油硫腐蚀分析方法

采用ASTM D1275-B腐蚀性硫检测方法和扫描电子显微镜技术,研究变压器绝缘油硫腐蚀的分析方法。对变压器绝缘油进行腐蚀性硫检测,判断油中有无腐蚀性硫;对硫腐蚀的铜片进行形貌和能谱分析,测量腐蚀产物中硫含量和腐蚀产物层的厚度。测量结果表明,硫腐蚀程度随硫含量和产物层厚度的增加而增大。变压器绝缘油硫腐蚀的形貌和能谱分析,弥补了腐蚀性硫检测方法在判断硫腐蚀程度方面的不足,该方法可以判断硫腐蚀程度,还能够判断腐蚀性硫检测结果的准确性,因此ASTM D1275-B法结合扫描电子显微镜技术是分析变压器绝缘油硫腐蚀的有效方法。     

广东电网变压器绝缘油中金属钝化剂含量普查及对策研究

变压器绝缘油中添加金属钝化剂可有效缓解腐蚀性硫对变压器的腐蚀。为掌握广东电网主变压器（主变）绝缘油中金属钝化剂含量变化情况,采用高效液相色谱法对广东电网添加金属钝化剂的208台主变绝缘油中金属钝化剂质量分数进行了普查。结果表明,金属钝化剂质量分数明显降低的主变有60台,其中降低幅度较大的有19台。参考国际相关标准,提出了变压器绝缘油中添加金属钝化剂后运行监督的措施。普查结果可为制定我国变压器绝缘油金属钝化剂添加和运行标准提供参考。     

变压器绝缘油硫腐蚀原因与对策

以福建电网一起变压器硫腐蚀故障为例,分析变压器绝缘油硫腐蚀产生的原因和应对措施.     

高效液相色谱测定绝缘油中金属钝化剂含量的方法研究

研究了高效液相色谱法测定绝缘油中金属钝化剂含量的方法,考查了可能造成检测干扰的因素,通过对试验条件的探究,不仅实现了绝缘油中金属钝化剂的定量检测,而且一次进样可以同时检测出绝缘油中3种有机物质(糠醛、金属钝化剂和抗氧化剂)的含量,为绝缘油中有机小分子物质的高效检测提供了参考。     

绝缘油中钝化剂含量检测方法的分析研究

阐述了绝缘油中为防止硫化亚铜沉积而添加的钝化剂的性能,介绍了对其样品前处理和高效液相色谱检测方法进行的研究。对上海地区部分已添加及未添加钝化剂的500 kV变压器绝缘油进行钝化剂含量检测,并提出相应的结论。     

变压器油硫腐蚀研究现状

介绍变压器油中硫腐蚀的机理,腐蚀性硫的定性、定量检测方法及硫腐蚀的处理措施等。     

大型变压器绝缘油中硫腐蚀的危害及防护对策研究

针对电网大型变压器在运行中发现的硫腐蚀问题,初步分析了产生硫腐蚀的原因及对设备安全运行的危害;在此基础上开展了防护对策的研究,提出了向运行设备绝缘油中添加钝化剂以避免硫腐蚀发生的解决方法,介绍了钝化剂技术在华东电网500kV变压器上的具体应用情况.     

钝化剂对变压器油中多重硫化物的防护效果及油品质量的影响

目前对钝化剂防护有效性的研究主要集中在单一硫化物方面,为此文中探究了含有多重腐蚀性硫情况下不同钝化剂防护效果差异以及钝化剂对油品质量的影响。采用含有多种腐蚀性硫化物的福建水口变电站运行油在150℃下进行加速老化试验,通过比较TTA、Irgamet39、T571这3种钝化剂在多重腐蚀性硫并存环境中的防护有效性,获得了3种钝化剂的最佳添加量。通过测试添加最佳浓度钝化剂后的新油及运行油的工频击穿电压、介质损耗因数、体积电阻率以及水分含量,对比分析了3种钝化剂对油品质量的影响。研究结果表明:3种钝化剂中,TTA的防护效果最佳,质量分数为50×10^-6即可保护铜片免受侵蚀,其它两种钝化剂即使质量分数达到200×10^-6也无法做到完全防护,只能延缓铜片受到的侵蚀。Irgamet39的加入对油样击穿电压、介质损耗因数、体积电阻率、油中水分等特征参量影响最小,T571钝化剂次之,TTA因其难溶于油,即使充分搅拌后仍然会对油品质量产生较大影响。综合考虑钝化剂对油品质量的影响与经济性,推荐在变压器运行一段时间之后,向油中添加100×10^-6...     

Research on influencing factors of corrosive sulfur attacking copper in insulating oil and prevention

The influencing factors (temperature, electric field, and oxygen) of sulfur attack in transformer oil are studied through comparative tests on new oil, oil in service, and these two oils with the deactivator additive BTA (benzotriazole, C₆H₄N₃H). The influence of these factors on the chemical reaction between copper and corrosive sulfur is analyzed in further. The results show that temperature, electric field, and oxygen can promote the reaction between copper and corrosive sulfur. Moreover, oxygen also accelerates the aging of the insulating oil. On the contrary, recharging nitrogen can remove oxygen and reduce sulfur's corrosive activity. Adding the BTA deactivator can also prevent corrosion, even during the accelerated aging of oil with oxygen. © 2013 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

变压器油中腐蚀性硫的研究进展及应用

综述了变压器油中腐蚀性硫的研究进展;结合研究现状,对贵州电网220kV及以上电压等级主变压器（含高抗）油进行腐蚀性硫的检测;对含腐蚀性硫的变压器油进行了添加钝化剂的处理,添加钝化剂前后的试验数据对比证实了这种处理方法的有效性,具有推广价值。     

Mechanism of increase of electrostatic charging tendency in insulating oil for oil‐immersed transformer

The mechanism of the increase in the electrostatic charging tendency (ECT) of insulating oil and causative compounds were investigated by accelerated deterioration tests with the addition of various compounds. Although the ECT of the insulating oil was almost constant when only sulfoxide compounds were added, a marked increase was observed when either hydrochloric acid or moisture, which was considered to be generated by the aging of insulating oil, was also added to oil containing sulfoxide compounds. It is assumed that the sulfonium ion, which is generated by the reaction between sulfoxide compounds and hydrogen ion, is the compound that directly contributes to the increase in the ECT. Hydrogen ions can be supplied from organic acids generated by the oxidation of hydrocarbons in aging insulating oil. It is considered that the increase in the ECT of insulating oil is caused by the generation of sulfoxides by the oxidation of sulfide, which are present in fresh oil (originating compounds), and the generation of sulfonium ions by a reaction between sulfoxide and hydrogen ions, which are formed during aging. © 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 176(4): 26–33, 2011; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21113     

Corrosion control by antioxidant DBPC in insulating oil

In order to evaluate corrosive sulfur in insulating oil quantitatively, wave length dispersive X-ray (WDX) technique has been reported (1) . Using this technique, antioxidant 2,6-di-tert-butyl-p-cresol (DBPC) was found to be effective to suppress corrosion caused by dibenzyl disulfide (DBDS). The effect of corrosion prevention continues for a long term when a certain amount of DBPC is added to oil. The durability of DBPC was also evaluated by HPLC. It is possible to add relatively a good deal of DBPC to oil because DBPC has higher solubility than passivator and little effect on dielectric strength. Furthermore, DBPC was used with passivator simultaneously, and corrosion control time was far extended by their synergy effect. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

矿物绝缘油中噻吩类非活性硫诱发绕组腐蚀的反应机理研究

矿物绝缘油中腐蚀活性较强的硫化物已被证实会诱发油浸式电力设备绝缘故障,在绝缘油精炼过程中会被去除。部分非活性硫因其高效抗氧化性保留于矿物绝缘油中以提高油品的氧化安定性。然而,非活性硫在油浸式电力设备运行条件下的活化问题及其对绝缘性能造成的影响并未得到关注。本文针对矿物绝缘油中的典型非活性硫噻吩类硫化物,聚焦油纸绝缘中非活性硫诱发绕组腐蚀的反应机理。采用材料物相分析方法探究噻吩类硫化物的热裂解产物,结合热解动力学分析方法,分析噻吩类硫化物在不同升温速率下的活化能变化规律,并开展非活性硫噻吩类硫化物在油纸绝缘热场作用下的试验研究。热裂解解气相色谱、质谱以及热解傅里叶红外光谱结果表明,噻吩类硫化物(噻吩、苯并噻吩、二苯并噻吩)在热解过程中的主要活化产物为具有极强腐蚀性与挥发性的H₂S。不同热解升温速率下,噻吩类硫化物的热重和微分热重曲线形状基本一致,其中噻吩最容易发生热解、其次是苯并噻吩、最后为二苯并噻吩。在油纸绝缘低温过热条件下,由于体系能量的不断积累,导致非活性硫噻吩类硫化物会发生活化进而生成低分子强腐蚀性硫化物,加剧了油品腐蚀性,最终导致油纸绝缘发生硫腐蚀。     

金属颗粒对绝缘油流注发展特性的影响研究

变压器在制造、运行和维修等过程中,其内部绝缘油难免会引入金属颗粒,为探究金属颗粒对油纸绝缘性能的影响,文中搭建并调试了油纸绝缘雷电冲击放电试验平台等,开展了金属颗粒对绝缘油流注发展特性影响试验研究,研究了不同浓度金属颗粒对绝缘油流注起始电压与发展过程中形态的影响,并通过COMSOL仿真平台进行验证。结果表明,金属颗粒会促进油中流注的起始与发展过程,流注停止长度和发展速度与颗粒浓度呈正相关,而绝缘油流注起始电压与击穿电压与颗粒浓度呈负相关,金属颗粒的引入会使得流注形态更加发散。分析认为油中金属颗粒与流注的相互作用是降低流注起始电压,加速流注发展,进而降低绝缘油击穿电压的主要原因。     

某电厂主变压器油中腐蚀性硫问题分析及处理措施

某电厂1号、2号主变压器油击穿电压偏低,总烃含量持续升高。为找出问题所在,对油品进行了一系列试验,包括扫描电镜扫描、元素分析、X射线衍射分析及腐蚀性硫试验,其结果为变压器油中全硫及腐蚀性硫分较高,变压器油发生了硫腐蚀,含硫物质与绕组材料（铜）发生反应后生成黑色的Cu2S及Cu4SO4（ＯＨ）6,影响变压器的绝缘性能,导致油中总烃含量升高。再生处理并辅以添加钝化剂的方法可降低油中全硫和腐蚀性硫分,减缓硫对铜片的腐蚀。     

油／气绝缘套管出线变压器现场试验方法

通过油／气套管和GIS连接的电力变压器是一种新型结构电力设备。对其进行介质损耗和电容测量试验,需要将SF6气室打开才能进行试验接线,现场处理难度大,并且容易在处理过程引起新的设备缺陷。文中介绍不打开SF6气室,对变压器进行介质损耗和电容测量的试验方法。理论分析和现场试验证明,该试验方法简单,测试数据可靠。     

Motion characteristics of a charged metal particle in insulating oil under flow state

Problems due to discharge by charged metal particles in insulating oil under flow state are examined in this study. The motion characteristics of a charged metal particle in a horizontal transformer oil tract are investigated, and a mechanical model of a charged metal particle under flowing oil and an AC field is proposed. The particle's equations of motion are numerically solved using the fourth‐order Runge–Kutta computational algorithm. The trajectory of a spherical iron particle in typical motion state under flowing oil and AC field is simulated. The influence on the motion characteristics of a charged metal particle in terms of the oil flow rate, electric field strength of the oil tract, particle scale, initial state, and particle rotation is analyzed. Results reveal that when a charged metal particle is moving fast along the direction of oil tract flow, reciprocating oscillation simultaneously occurs in the vertical direction. Its trajectory is significantly affected by the oil flow rate, the electric field strength of the oil tract, particle scale, initial state, and particle rotation. Moreover, the degree of oscillation of the charged metal particle may be the main cause of degradation of the insulating oil under flow state. © 2017 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.