服役25年变压器铁心中取向硅钢性能演变规律

研究了服役25年S9型配电变压器空载性能及铁心中取向硅钢的磁性能与涂层性能变化规律。运行25年后,变压器空载损耗上升至105.29 W,取向硅钢铁损P1.7为1.48 W/kg;取自铁心下轭1/4处、A相心柱中间位置、B相心柱靠近T节点处取向硅钢的绝缘涂层劣化程度依次上升,劣化最严重的B相心柱靠近T节点处部分硅钢片表面电阻系数低至2.6Ω·cm~2,涂层附着性为D级,扫描电镜下观察到涂层受腐蚀脱落。采用Infolytica电磁仿真软件模拟铁心温度场分布发现,铁心不同位置处运行温差可达9.1℃,长期处于相对较高温度、变压器油(酸和硫含量上升)及叠片间稀薄空气环境下取向硅钢绝缘涂层劣化严重。讨论了长时间服役后的二次取向电工钢片在配电变压器中的应用屏蔽措施。     

1级能效配电变压器用低铁损取向硅钢B18R065和B20R070

近年来,为了降低输配电变压器损耗,减少二氧化碳排放,世界各主要国家都发布了强制性高能效配电变压器标准,中国在2013年发布GB20052—2013《三相配电变压器能效限定值及能效等级》新标准。变压器标准更新和能效等级提升,必然要求变压器铁芯原材料性能的提升。在此背景下,宝钢开发了低铁损取向硅钢B18R065和B20R070,并已经成功用于制造1级能效变压器,成为世界上能同时供应0.20 mm和0.18 mm规格髙磁感取向硅钢的厂家。对B18R065和B20R070这两种牌号的开发原理、性能和用户使用情况进行介绍,以期对变压器制造厂家选材起到参考作用。     

无底层取向硅钢工艺与进展

介绍无底层取向硅钢的优点、制备工艺及发展情况,论述了无底层取向硅钢的工艺难点和应用前景。无底层取向硅钢具有良好的磁性能和加工性能,已在大型旋转电机领域获得应用;具有超低铁芯损耗的镜面无底层取向硅钢,如在张力涂层技术与工艺方面获得突破,在超低损耗和低噪音变压器等领域具有广阔的应用前景。     

取向硅钢绝缘涂层绝缘性能影响因素分析

绝缘性能是取向硅钢的一个重要指标,本文研究了涂层烧结温度、涂液中硅溶胶含量、绝缘涂层涂敷量对取向硅钢绝缘性能的影响。研究发现:烧结温度升高,涂层表面逐渐出现微观裂纹,钢板表面在850℃下烧结时出现裂纹,退火温度达到900℃后,涂层表面裂纹会急剧增加,导致涂层绝缘性降低。在相同烧结温度下,提高涂液中SiO2含量,将导致涂层表面出现微观裂纹,不利于涂层的绝缘性能。在相同烧结温度下,提高绝缘涂层的涂敷量,有利于提高钢板的层间电阻。在烧结温度为850℃,涂敷量为6 g/m2时,钢板层间电阻可达到82.6Ω·cm2。     

变压器铁芯材料的技术动向

<正>铁芯作为变压器的核心部件,所用的材料对电力变压器和电子变压器的性能和价格都起着关键性作用。而取向硅钢是电力变压器和电子变压器用量最多的铁芯材料,冷轧取向硅钢大量用于工频电子变压器、频电子变压器和电子变压器中。因此,硅钢的市场和技术方向的动向,对电力变压器和电子变压器都会产生重大影响。在改进电力变压器用的冷轧取向硅钢性能方面的技术进展有:     

三相搭接铁芯非晶配电变压器

介绍了非晶配电变压器铁芯的结构、国外搭接铁芯非晶配电变压器的制造情况以及用国产铁基非晶带制造搭接铁芯的工艺过程和主要性能，同时还介绍了用这种搭接铁芯制造的两种配电变压器的情况及应用前景。     

取向硅钢涂层对噪音特性的影响

取向硅钢片磁致伸缩是变压器噪音来源的主要因素,本文研究了取向硅钢片硅酸镁底层和磷酸盐涂层对磁致伸缩的影响。结果表明：取向硅钢表面的硅酸镁底层和磷酸盐涂层可降低取向硅钢的磁致伸缩;增加绝缘涂层的厚度可减少杂畴和90°畴,改善取向硅钢的噪音性能。     

取向硅钢表面涂层结构对其性能的影响

通过扫描电镜观察取向硅钢截面涂层结构,分析其对取向硅钢绝缘性能、附着性、铁损的影响。研究结果表明:取向硅钢底层的钉扎、硅酸镁涂层、磷酸盐涂层共同作用影响着取向硅钢的性能;取向硅钢底层质量差会导致其绝缘性能和磁性能差;底层钉扎对铁损影响较大,钉扎厚度为3μm时,取向硅钢的铁损低且附着性好;硅酸镁涂层越致密均匀,取向硅钢的附着性越优良;钢板的底层厚度与磷酸盐涂层厚度同时影响着取向硅钢的绝缘性能,在相同的底层厚度下,提高磷酸盐涂层的厚度有利于提高钢板的层间电阻。     

在我国申请的冷轧取向硅钢涂层专利技术分析

对1999—2019年在我国申请的冷轧取向硅钢涂层的专利数量、专利技术领域分布进行了统计。统计分析结果表明:目前在我国申请的冷轧取向硅钢涂层专利有121项,其中国内有96项,国外有25项,典型的专利技术主要有底层质量改善、无底层形成、含铬绝缘涂层及无铬环保绝缘涂层等,硅钢涂层发展的趋势是以无铬环保的绝缘涂层为主。     

太钢冷轧无取向硅钢绝缘涂层的发展及技术进步

简述了国内和太钢冷轧无取向硅钢绝缘涂层的发展历史及现状,介绍了太钢目前不同类型涂层的主要性能、应用领域,及近些年来涂层发展过程中生产技术的进步,主要包括C5薄环保涂层自主开发、C6极厚涂层国产化、自粘结涂层工艺开发,并提出了绝缘涂层下一步的发展方向。     

Performance evaluation law of grain- oriented silicon steel in transformer core after 25years service

The no- load characteristics of S9 distribution transformer and the magnetic properties as well as coating performance of grain- oriented silicon steel were studied. After 25years in service, the no- load loss of transformer increased to 105. 29W, while the core loss of silicon steel was 1. 48W/kg. The degradation degree of insulation coating, which had serviced about 25years, showed upward trend in position 1(bottom iron yoke), position 2(phase A core column), and position 3(phase B core column), respectively. The silicon steel located at phase B core column shows a dangerous surface resistivity of 2. 6????cm2 and an adhesion of D level. Simulation result of temperature distribution base on the Infolytica software shows that the temperature difference in transformer core reaches about 9. 1??, and the phosphate coating is deteriorated seriously after working in high temperature, transformer oil(with the increased contents of acid and sulfur) and air environment for a long time. The shielding measures of second- used silicon steel sheets in distribution transformer were discussed.     

Recent development of electrical steel sheets in China Steel Corporation

The major applications of electrical steel（ES） sheets are motors,transformers,etc.In recent years, the raise of crude oil price and increasing environmental consciousness trigger the demands for saving energy and reducing CO₂ emissions,which greatly accelerate the development of high quality ES sheets.To meet the quality requirements of high efficiency motors and transformers,high grade ES sheets with high flux density are continuously developed and introduced to the market.Meanwhile,the price competition and quality improvement of general grades are important for the lower end application.The iron loss of 50CS1300（50A1300） is significantly reduced by controlling some key parameters.Other than the normal grade,the highest grades of nonoriented （NO） ES are successfully developed recently.And all specifications of 0.50 and 0.35 mm among JIS C 2552 specification could be provided by CSC.As to the insulation coating development,the Cr-free insulation coating has been introduced to the market due to the environmental concern,and has been enormously adopted in Taiwan market.Furthermore,the thicker insulation coating technology has been successfully developed for specific wind power generator application.The newly developed products and quality improvements of electrical steel sheets in China Steel are introduced in this paper.     

Influence of silicon coating on the corrosion resistance of Zn-Al-Mg-RE-Si alloy

The electric arc spraying method was used to prepare the Zn-Al-Mg-RE-Si alloy coating with different content of silicon. The corrosion resisting property was measured by copper accelerated salt spray (CASS) and corrosion weightless test. The influence of silicon content on the corrosion resisting property was investigated by XRD, SEM, polarization curve and electrochemical impedance spectroscopy (EIS) and the electrochemical property of coating in the corrosion process was analyzed. The results showed that the density of coating was improved significantly since the major nonequilibrium glass-like state phase was composed of silicon and other metals existed in the Zn-Al-Mg-RE-Si alloy coating, which prevented the corrosive medium and retarded the corrosion velocity because of compact corrosion products in the corrosion embryo. The Zn-Al-Mg-RE-Si coating had better corrosion resistance than the Zn-Al-Mg-RE because of more positive potential, half corrosion current density and double electrochemical reaction resistance.     

Influence of silicon coating on the corrosion resistance of Zn-Al-Mg-RE-Si alloy

The electric arc spraying method was used to prepare the Zn-Al-Mg-RE-Si alloy coating with different content of silicon.The corrosion resisting property was measured by copper accelerated salt spray(CASS) and corrosion weightless test.The influence of silicon content on the corrosion resisting property was investigated by XRD,SEM,polarization curve and electrochemical impedance spectroscopy(EIS) and the electrochemical property of coating in the corrosion process was analyzed.The results showed that the density of coating was improved significantly since the major nonequilibrium glass-like state phase was composed of silicon and other metals existed in the Zn-Al-Mg-RE-Si alloy coating,which prevented the corrosive medium and retarded the corrosion velocity because of compact corrosion products in the corrosion embryo.The Zn-Al-Mg-RE-Si coating had better corrosion resistance than the Zn-Al-Mg-RE because of more positive potential,half corrosion current density and double electrochemical reaction resistance.     

薄规格取向硅钢电磁特性及在中低频率电力装备中的应用#br#

针对工频配电网中节能变压器、兆瓦级DC/DC变换器中频隔离变压器、柔性低频交流输电领域低频变压器等电力装备对高性能取向硅钢的应用需求,采用任意波形磁场激励软磁测量系统,研究了0.10~0.27 mm不同牌号取向硅钢在不同工作频率下的电磁特性,探讨了薄规格取向硅钢在中低频电力装备中的应用前景。与0.10 mm超薄取向硅钢相比,0.18 mm高磁感取向硅钢在15~400 Hz中低频率范围具有更低的损耗特征。0.18 mm产品不仅在轧向的铁损低于0.23 mm和0.27 mm产品,在横向也具有最低损耗优势;但对于相同厚度材料,轧向低损耗并不意味着横向同样具有低损耗。分析了不同厚度取向硅钢电磁特性差异及原因,结果可支撑各类型变压器铁心材料选型。结合工频、中频和低频领域电力装备技术发展对铁心材料性能要求,展望了薄规格取向硅钢未来的发展趋势。     

新贸易环境下我国取向硅钢的发展机遇与使命

取向硅钢是关系电力发展的重要材料，公平的取向硅钢市场环境有助于我国输变电产业链的健康发展。国家依法采取的反倾销贸易措施，为我国取向硅钢及输变电产业链营造了公平、健康的市场环境。面向未来，我国取向硅钢产业使命在肩，要在自身进步的同时，与变压器企业携手领创用材等级提升，实现产业链高质量发展，并将继续为国家“双碳”战略做出新的贡献。     

0.18 mm极低损耗取向硅钢电磁特性与铁心性能仿真分析#br#

基于极低损耗取向硅钢研制S15型超高能效变压器对于进一步推动电网节能增效具有重要意义。采用任意波形磁场激励测量系统对比研究了0.18 mm规格取向硅钢、1K101-S普通型、1K102-P高磁感型非晶合金的磁性能及磁致伸缩噪声特性,并分析了0.18 mm取向硅钢在谐波、直流偏磁等复杂工况下的损耗特性,采用MagNet有限元分析软件开展了0.18 mm极低损耗硅钢S15型变压器铁心、绕组建模与仿真分析。结果表明,磁通密度为1.35 T时,18QH065牌号取向硅钢的铁损低至0.349 W/kg,不断接近非晶合金水平,磁感B800则比非晶带材高0.32~0.40 T;取向硅钢的磁致伸缩系数λp-p为0.29×10-6,低于非晶合金超1个数量级。与0.23~0.30 mm常规厚度硅钢相比,0.18 mm薄规格硅钢的谐波损耗优势明显,10%含量的3次、5次谐波损耗与正常工况相比分别上升12.9 %、16.0 %;直流偏置磁场大小对取向硅钢铁损的影响主要在低磁密区,在1.9 T以上0~150 A/m偏置磁场下的铁损几乎相同。设计的10 kV/630 kVA变压器空载损耗仿真计算值为392.5 W,比国标GB 20052—2013中能效1级硅钢变压器的限定值低约31.1 %,噪声比同等容量非晶合金变压器低约10 dB,具有显著的节能和环保优势。     

M152钢基体超音速火焰喷涂WC-17Co涂层性能研究

采用超音速火焰喷涂技术在M152钢上制备了WC-17Co涂层。对WC-17Co涂层的耐磨性能和耐蚀性能进行了研究。结果表明超音速火焰喷涂WC-17Co涂层显著提高了M152钢基体的抗盐雾腐蚀性能,同时WC-17Co涂层具有优异的抗氧化性能和耐磨性能,可用于M152钢零件中温区域的耐磨、耐蚀防护。     

取向硅钢产品表面质量检测对比分析

检测了3家不同企业取向硅钢成品板表征表面质量的指标,同时对表面层采用扫描电镜和能谱仪进行微观结构和化学成分组成进行检测。对比不同企业的成品板表面质量指标和微观结构发现：不同企业的取向硅钢表面层质量有差异,A产品表面绝缘电阻高于B和C产品且后者表面绝缘电阻相当,B和C产品涂层附着性和耐蚀性优于A产品。从微观形貌和成分分析上可以得出,A产品绝缘层厚是表面绝缘电阻大的原因之一,B、C产品附着性级别好是由于钉扎在基体的颗粒大或是距离硅酸镁较近,A产品表面有裂纹导致耐蚀性下降。