单相工频感应炉与电源的连接

有色加工行业中，单相工频感应电炉应用日趋广泛。对电网页言，单相负荷将使电网质量下降，从而影响电网中的其他用户。为保证电网捏，往往希望三相负荷尺量平衡，但由于工频感应炉这类单相负荷容量较大，用其他负荷难以使电网三相负荷平衡。为此，笔者在某有色金属加工厂感应炉的设计中采用了相平衡器装置，即由平衡电容器、平衡电抗器与经过补偿电炉按三角形接法接成了人为的三相负荷，再将此负荷接入电网，具有三相平衡负荷的性质，因此消除了单相工频炉所造成的影响。     

供电线路三相负荷不平衡的危害及解决的方法

若电器负荷匹配不均易造成供电线路三相电压不平衡,电压偏移值增大,电压波形产生畸变,线损增加,致使原供电系统不堪重负,严重时引起大面积停电,中性线烧断,三相电压不平衡,烧坏电器的后果.通过对三相不平衡电流附加线损的计算,结合部分低压供电系统的改进实例,论证低压供电系统对调整不平衡负荷的重要性以及进行改造的必要性和良好效益.     

三相不平衡负载新型无功补偿算法的研究

三相不平衡负荷对电网造成很大的危害,本文通过对现有不平衡补偿算法进行改进,进而建立三相四线制接线不平衡无功补偿模型。结果表明,该补偿模型可以使三相不平衡情况得到有效改善,获得较好的电能质量,并且达到较好的节电效果。     

有芯工频感应炉三相平衡调节若干问题的研究

本文介绍上引法连铸机组用有芯工频感应炉的三相平衡调节,应用矢量分析法分析调试及运行维护过程中遇到的问题,提出处理措施,同时指出供电系统三相负荷电流不平衡的危害.     

铁路信号微机自控系统对电源的要求及措施

铁路信号自控系统是一级供电负荷,要求有两路高质量的供电电源。三相电源负荷不平衡,地线干扰,零线和地线间电压过高会引起铁路信号设备错误动作,分析解决方法,提出具体措施。     

谈配电变压器节电的运行管理措施

本文简略地介绍如何组织变压器经济运行,变压器分接开关的节电运行和如何平衡变压器的三相负荷,调整负荷曲线,以降低变压器负载损耗,均衡变压器负荷。     

三相对称负荷低压配电系统中性点新运行方式的探讨

本文通过分析了三相对称负荷低压配电系统中性点接地和不接地的优缺点,提出了三相对称负荷低压系统中性点运行方式的改进措施。     

中小型三相交流硅锰炉电气特性不平衡分析

中小型三相交流矿热炉存在严重的电气参数不平衡问题,导致冶炼过程炉况不稳、功率因数低、电耗高,难以实现冶炼过程三相熔池功率和温度场的平衡控制.以容量为12.5 MVA的三相交流硅锰炉为对象,在对其关键电气参数进行检测与计算的基础上,分析了三相短网不平衡、现有人工操作机制以及炉内变化所致不平衡对三相交流矿热炉电气特性的影响...     

三相平衡节电技术机理研究

介绍了三相平衡节电技术概念、地位和作用，并由浅入深地分析了三相平衡节电系统结构、三相平衡技术核心原理，用矢量分析方法分析了三相平衡技术所产生的理论成效。     

工业炉预热段循环风机电机三相不平衡问题研究

介绍了梅山钢铁连退机组预热段循环风机电机三相不平衡的现象,阐述了电机三相不平衡的危害,对产生预热段循环风机电机三相不平衡原因进行了深入的分析,并对该典型案例提出了针对性的改善建议。     

株冶主供动力变压器效率的分析与提高

本文通过对株冶4台主供动力变压器经济负载区的分析推导，阐述了在利用现有设备基础上，调整其容量与负荷的达配状况，提高变压器运行效率的可行性和, 分析了负荷调整后的效果与效益。     

相序接法对电能计量的影响

阐述了电能计量表的二次接线正确与否对电度表计量准确率的影响 ,着重讲逆电压相序接线对电能计量的影响 .分析表明 ,正相序接线 ,而且电流按照与电压相位相对应接入 ,则不影响电能计量表的计量准确率 .逆电压相序接线 ,而且电流不按照与电压相位相对应接入 ,则电能计量表会随负载是感性还是容性而产生快转和慢转现象 .无功计量表在系统没有无功补偿时则会发生反转     

Phase-stress partition during uniaxial tensile loading of a TiC-particulate-reinforced Al composite

Using neutron diffraction, we measured during in situ loading the lattice elastic mean phase (LEMP) strains in the matrix and reinforcement of a 15 vol pct TiC-particulate-reinforced 2219 Al composite. From the strain components longitudinal to and transverse to loading, the in situ normal phase stresses (average normal stresses in the constituent phases) were obtained through Hooke’s law. The internal stress partition between the matrix and reinforcement, i.e., load sharing, can then be inferred. Internal stress development was also modeled using the finite-element method (FEM), showing good agreement with the experimental results. Both indicate that the relationship between the LEMP strains/phase stresses and the applied load noticeably deviates from linearity during composite microyielding, long before the nominal 0.2 pct proof stress is reached. The nonlinearity arises (despite the linear elastic relationship between phase stresses and LEMP strains) because the applied traction is not synonymous with the phase stresses, and the ratio of phase stresses may vary during loading. Notably, the morphology of the LEMP strain development with applied load differs in the directions parallel to or perpendicular to the load. The differences are explained by considering the evolution of local matrix plasticity. Thermal residual stresses and inelastic stress relaxation, driven by interfacial diffusion, are also discussed.     

降低蒸发汽耗的有效途径

本详细论述通过改造减温减压、改造蒸发器进汽带、及时补充保温减少热损失、减少非生产水进流程减轻蒸发负担、缩短蒸发器水洗周期，提高蒸发器产能等措施来降低蒸发汽耗的途径。     

调荷节电是企业节资降本的有效途径

本阐述对生前和电在运行中如何调荷节电,降低电耗,减少电费支出进行分析,使企业真正大用电管理中走出一条有质量效益型的管理道路。     

浅谈工矿企业三相异步电动机的节电措施

三相异步电动机作为原动机，拖动各种生产机械设备，是工矿企业的主要用电设备。本简述了三角异步电动机运行中的效率，功率因数，负载率和功率的关系的关系及各种节电措施。     

Theory,experiments and numerical modelling of phase transformations with emphasis on TRIP

This paper presents an overview of the co‐operative efforts aiming at the correct characterisation of the thermo‐mechanical behaviour of materials during the process of a phase change. In the first section the physical conditions for the onset of transformation processes, either diffusive or massive or displacive, expressed in terms of the chemical driving forces in a multi‐component system are derived on a very general basis. Introducing appropriate expressions for the chemical as well as the mechanical dissipation based on jump conditions of quantities such as the deformation rate and the diffusive fluxes at the moving interface allows to formulate proper transformation criteria. No fluxes will occur in the case of displacive, i.e. martensitic transformation which is responsible for the TRIP phenomenon. The mechanism governing the selection of a particular martensitic variant of the product phase out of a discrete number of possible variants is described in the paper. The underlying ideas and tools supplied by continuum mechanics eventually leading to a transformation condition for martensitic transformation are summarised in the appendix. The second section of the paper shows some aspects of a comprehensive experimental program investigating the thermo‐mechanical behaviour of a maraging steel with very advantageous properties in the transformation regime. It allows to filter out the TRIP strain evolution during transformation from the total strain measured by means of a multiaxial tension torsion dilatometer equipment. The focus is put on finding a material law that is valid also for non‐proportional loading paths. Unlike the predictions of traditional constitutive relationships the TRIP strain rate exhibits a significant drop if the external load is removed during the progress of transformation suggesting the existence of a transformation related backstress. Finally a method is demonstrated how to validate the experimental findings by means of a numerical algorithm. Based on the physical principles explained in the first part of the paper a subroutine can be devised and implemented into a commercial finite element code that allows to simulate the behaviour of the material represented by a unit cell. The simulations yield realistic results for the transformation kinetics, the load‐displacement curves as well as the material response for non‐proportional loading paths.     

<Emphasis Type="Italic">In-Situ</Emphasis> Synchrotron X-ray Diffraction Studies on Effects of Plastic and Elastic Loading on bcc Phase Transformations of a 3rd Generation 1 GPa Advanced High Strength Steel

In this paper, we describe the effects of mechanical loading on bcc-to-bcc phase transformations of an Advanced High Strength Steel during cooling. In-situ synchrotron diffraction was employed to measure time–temperature–load diffraction patterns. Calculations were made of the volume fractions of the phases, the transformation kinetics, and the austenite lattice parameter during cooling and simultaneous loading. In addition, volume fractions and lattice parameters of retained austenite at room temperature under different loading conditions were obtained. The results show that applying a load during cooling of the fcc phase significantly increases the volume fraction of a bcc phase before the start of the martensitic transformation. The kinetics of phase transformations were affected by the applied loads. The volume fraction and lattice parameter of retained austenite at room temperature vary in different samples and the highest retained austenite and the largest lattice parameter were obtained in the sample subjected to the highest load.     

三相异步电动机轻载运行的电能损失及预防

三相异步电动机的轻载运行,是很不经济的。文中重点分析了电动机轻载运行时,电能损耗产生的原因及计算方法,并介绍了预防电动机轻载运行的措施。