变压器6／6＋4／6斜接缝多级塔接铁心

定量分析了铁心片接缝处局部磁密随塔接接缝级数变化的关系，并对６／６三级塔接铁心、６／６＋４／６三级搭接铁心、６／６四级二级混合搭接铁心、６／６＋４／６四级二级混合搭接铁心的磁性能进行了对比、建议采用６／６＋４／６片型，认为其具有省工、省料、性能好的特点。     

基因控制遗传算法在变压器铁心截面优化设计中的应用

分析了铁心最小级片宽下限的选择依据,给出了叠厚的递推公式,提出了采用基因控制遗传算法进行铁心截面的优化设计.     

主变压器铁心故障判断与分析

为了查找110 kV堡子店2号主变压器投运后色谱异常的原因,采用色谱跟踪结合电气试验数据进行综合分析,证实铁心片间短路是该故障的诱因,并对短路缺陷进行了处理,提出在变压器安装吊芯检查时,应将铁心连片解开,测量铁心级间绝缘电阻,防止铁心片间短路导致运行故障。     

日本安川电机制造厂的小型电动机铁心自动叠装方法

普通小型电动机的定子铁心片和转子铁心片,都是用成卷硅钢片在高速压力机的级进模上连续冲制的。冲片从压力机料道取出后,分别进行分台计量。然后,定子铁心按需要的高度叠装和紧固。转子铁心在假轴上叠装、扭斜度、临时固定、压力铸铝,压铸后再取出假轴。     

变压器铁心最优截面设计计算方法

论述了变压器铁心在最小级片宽和级数约束条件下最优截面的设计计算方法，并提供了详细的设计计算数据。     

电机转子铁心高效迭压工具的设计

1　概　述随着人民生活水平的提高 ,人们对机电产品、高档家用电器的需求量大 ,对于规模经济生产的风扇电机、洗衣机电机、脱水机电机、冰箱电机等系列电机 ,机电行业引进了相当数量的高速冲床 ,多工位级进模 ,能完成定转子冲片的冲裁。定转子斜直槽铁心扣铆的是少数 ,大多数的高速冲床、多工位级进模仅能完成定转子冲片的冲制 ,自动理片。因此多数用单片联冲 ,高速冲生产冲片及部分铁心部件 ,大量的铁心迭压仍靠专用迭压工具完成。2　转子铁心高效迭压工具的组成由于冷轧电工钢价格上的差异等原因 ,我厂的高速冲床、多工位级进模未能发挥应…     

变压器铁心的绑扎

铁心是变压器的重要组成部分。它既是变压器的磁通路，又是变压器的支撑核心。因此，对铁心制造不仅有精度要求，而且对心柱的填充系数和机械强度都有较高要求。通过对变压器铁心的有效绑扎，可在铁心柱最小级片上产生０．３～０．４ＭＰａ的压强，可以满足对铁心柱机械强...     

工业缝纫机电动机定子铁心压铆模

定子铁心叠压铆装是电机生产中的一道重要工序之一。它是将一定数量的铁心冲片经过理片压紧铆牢组合成一个整体,使之满足电机的电磁性能,在运动中不松动,片间绝缘好,铁心损耗小等。因此叠压铆紧必须保证定子铁心的长度、内径精度和外径精度。我厂生产的出口工业缝纫机电动机定子铁心是由数片硅钢片叠压,用8根铆钉铆合而成。定子铁心技术要求:外径公差不得超过0.103mm,定子内外圆同轴度不得超过0.10mm。     

铁心异常时基于异频电流激励法的定子铁心损耗试验分析

为防止发电机在运行中因片间绝缘损坏,造成短路,引起局部过热,甚至危及机组的安全运行,需要对发电机的定子铁心进行损耗试验。对于试验方案在进行大型机组试验时存在绕线困难等问题,提出了一种采用异频电流激励法进行发电机定子铁心损耗试验的方法。建立铁心存在短路缺陷情况下的有限元仿真模型,通过对比工频大电流激励和异频小电流激励下铁心的发热情况,论证了异频小电流可以替代工频大电流进行铁心损耗试验。     

绝缘调节片结构的改进

1前言 在110kV级变压器结构设计中,铁心上梁(从上轭外用于连接高低压夹件的结构件)、侧梁(从柱外用于连接两夹件的结构件)的长度一般要比夹件内距小10mm左右,以适应铁心的叠装裕度及部件加工精度所带来的影响.为了增强螺栓连接的可靠性,使夹件与侧梁、上梁紧固成一个整体,我们在此位置上放置绝缘调节片来填充此空隙.当上梁或侧梁到夹件腹板距离小时,我们去掉绝缘调节片;反之,增加绝缘调节片.     

一种新型数控横剪线

介绍了用于变压器铁心片剪切的小型数控横剪线的结构、功能及其主要性能参数。     

节约变压器铁心硅钢片的方法

介绍了节约变压器铁心硅钢片的方法,并以实际产品为例进行了验证.     

降低硅钢片用量的措施

针对大型电力变压器铁心的特点,介绍了降低硅钢片用量的措施.     

一种宽频带微电流传感器的设计

为测量陡脉冲小信号,经磁芯选择、参数优化研制了一种罗科夫斯基线圈宽带微电流传感器。测试表明其线性度好、回差变化小、阶跃响应时间快,带宽396 kHz~120 MHz,灵敏度3.27 V/A,适于陡脉冲小信号测量。     

非正弦电压下硅钢片材料特性的预测

采用谐波分析法对非正弦供电的变压器进行了仿真,提出了一个基于神经网络的硅钢片材料特性的预测模型.     

硅钢片磁性能自动测量系统的研制

介绍了使用25cm爱泼斯坦方圈测量硅钢片磁性能的测量原理及自动测量系统的的系统与硬件设计,描述了自动测量系统的软件设计.     

Impact of phonon scattering in Si/GaAs/InGaAs nanowires and FinFets: a NEGF perspective

This paper reviews our previous theoretical studies and gives further insight into phonon scattering in 3D small nanotransistors using non-equilibrium Green function methodology. The focus is on very small gate-all-around nanowires with Si, GaAs or InGaAs cores. We have calculated phonon-limited mobility and transfer characteristics for a variety of cross-sections at low and high drain bias. The nanowire cross-sectional area is shown to have a significant impact on the phonon-limited mobility and on the current reduction. In a study of narrow Si nanowires we have examined the spatially resolved power dissipation and the validity of Joule’s law. Our results show that only a fraction of the power is dissipated inside the drain region even for a relatively large simulated length extension (approximately 30 nm). When considering large source regions in the simulation domain, at low gate bias, a slight cooling of the source is observed. We have also studied the impact of the real part of phonon scattering self-energy on a narrow nanowire transistor. This real part is usually neglected in nanotransistor simulation, whereas we compute its impact on current–voltage characteristic and mobility. At low gate bias, the imaginary part strongly underestimated the current and the mobility by 50 %. At high gate bias, the two mobilities are similar and the effect on the current is negligible.     

轻质铝夹芯板抗冲击性能有限元分析

为了研究夹芯板在爆炸载荷作用下产生较大塑性变形及吸能特性,本文应用非线性有限元分析程序LS-DYNA V970（Livermore Software Technology Corporation）在HP-J6750工作站上完成爆炸冲击载荷作用下相同质量的单铝板、蜂窝夹芯板和波纹夹芯板的动力响应过程模拟。重点研究了夹芯板的吸能特性以及夹芯板各部分的吸能变化规律。在考虑有限变形情况下,相同质量下夹心板比单板具有更强的抗冲击性能和更小的变形。对研究夹芯板抗冲击性能提供了有效的近似方法。     

硅橡胶憎水迁移机理的研究

硅橡胶绝缘材料良好的憎水迁移性,使其在电力系统外绝缘中得到了广泛的应用。但目前对硅橡胶憎水迁移机理还有较大争议。采用GC－MS方法证明了小分子硅氧烷迁移理论,并对硅橡胶憎水迁移机理进行了深入的探讨。     

Silicone Transformer Liquid: Use, Maintenance, and Safety

Silicone transformer liquid has been in use in over 10 000 small and medium power transformers in the United States since 1972. In this time, the reliability and performance of silicone liquid has been proven. Silicone liquid is chemically inert and thermally stable. These characteristics will allow for a long and useful life and ease of reclaiming contaminated liquid. Similar procedures are used to process and test silicone liquid and mineral oil. Transformer designs have been modified in only minor ways to accommodate the differences between silicone, mineral oil, and askarel. The coefficient of expansion, the heat transfer characteristics, and the dielectric properties have all been thoroughly investigated. Silicone fluid has been used in new and retrofilled transformers without any unusual or premium design features. In a monitoring program, no water contamination, leaking, overheating or any other operational problem were experienced in over three million documented hours of service in all kinds of environments. The safety of silicone liquid has been established through thorough testing and field experience. The very low heat release rates and unique burning characteristics combine to make silicone a very safe material for use in power transformers. In addition, silicone liquids are among the least toxic of all commercial chemicals. This, and their ecological compatibility, make silicone a safe environmental choice in replacing askarel.