化学交联三层共挤相邻规格导体换规不停车生产技术的浅析

交联聚乙烯中、高压电力电缆绝缘挤制多采用三层共挤连续交联型机组。这种型式的交联机组在挤制绝缘线芯(包括导体屏蔽、绝缘和绝缘屏蔽)时,每次变换导体规格就必须停机并更换挤出模具,这样就会将交联管内60~80 m长的绝缘线芯报废,而开机后又会浪费约150 m长绝缘线芯,浪费惊人。采用相邻规格导体不停机换模具而连续生产,这可以大大降低材料和能源的浪费,提高生产率,降低产品成本。     

高压电缆铝护套三种制作工艺的性能对比与分析

连续包覆挤铝技术制造电缆铝护套是连续挤压技术的进一步发展,是一种高效节能的新工艺。文中主要对高压交联聚乙烯(XLPE)电力电缆不同制造工艺的挤铝、压铝、氩弧焊铝护套进行力学性能和显微结构的分析,结果表明,挤铝护套的力学性能和显微组织优于氩弧焊铝护套,而压铝护套和挤铝护套无明显差别。     

交联副产物对交联聚乙烯电缆绝缘热老化性能影响的探讨

本文叙述了交联副产物对交联聚乙烯电缆绝缘热老化性能的影响,给出了交联副产物的浓度,指出了对挤包后的交联聚乙烯绝缘线芯进行热处理的必要性。     

我国高压XLPE绝缘电缆线路的竣工试验

本文详细分析及论述了挤包绝缘电缆（主要为交联聚乙烯绝缘电缆）线路的竣工试验采用直流电压试验不能有效地检出有缺陷的电缆主绝缘及附件绝缘。对可能取代直流电压试验的几种竣工试验方法研究探索情况作了适用性的分析介绍。说明交流电压试验是目前相对比较有效且不会损伤挤包绝缘电缆线路电缆主绝缘及附件绝缘的竣工试验方法。最后对我国高压交联聚乙烯绝缘电缆线路的竣工试验方法及要求提出建议。     

可交联半导电屏蔽料的研究

交联聚乙烯绝缘电力电缆用可交联半导电料挤包屏蔽,在工艺上和电缆内在质量上均比绕包半导电带优越.作为可交联半导电屏蔽料的主要组份,所选用的树脂(或弹性体)基料,应是在添加大量炭黑后仍能保持良好挤出性能和机械物理性能的高分子材料;导电炭黑应具有较大的吸油量和比表面积,粒径小并保证其分散性,纯度要高;抗氧剂应与导电炭黑及交联剂有协同效果,兼具抗铜害性能;交联剂的选挤应注意与交联绝缘在加工温度、交联速率、交联曲线和交联程度等方面的匹配.据此研制的可交联半导电屏蔽料,完全能满足交联聚乙烯电缆的实际生产要求.     

改善交联电缆绝缘屏蔽料挤出性能的措施

改善交联电缆绝缘屏蔽料挤出性能的措施沈阳电缆厂郑尚峰主题词交联聚乙烯绝缘电力电缆；绝缘屏蔽；有机半导电材料；改进摊ｋＶ及以下交联聚乙烯绝缘电力电缆用绝缘屏蔽，通常是用挤包的可剥离半导电科。ｊ这种半导电料系采用ＥＶＡ做基料，加入其它助剂混合而成。我们三...     

35kV交联电缆终端头安装过程中出现问题的分析

大唐洛阳首阳山发电厂水源地变压器高压侧35kV电缆终端头以外单芯处绝缘部位多次出现绝缘损坏故障,严重影响机组安全运行。通过对故障的处理及原因分析,使电厂检修人员掌握了35kV交联电缆终端头的制作工艺,电缆运行正常。     

275kV交联电缆用挤出模注式连接盒

交联电缆具有许多优良特性,已被运用于长距离地下线路中,因此有必要开发与电缆同等的高可靠性的中间接头盒。现已研制出的275kV 电缆的中间接头盒,系采用与制适电缆相同的工艺,即在施工现场将混入交联剂的树脂挤出并交联成模注式的接头(简称 EMJ).介绍了275kV 交联电缆用的 EMJ 接头的设计、制作及电性能试验。     

挤包绝缘高压直流电缆应用现状与研究展望

挤包绝缘高压直流电缆已成为远距离、大容量输电线路建设的主要装备之一,现阶段广泛应用的挤包绝缘直流电缆以交联聚乙烯(XLPE)绝缘为主。针对XLPE绝缘高压直流电缆研发和应用中的绝缘空间电荷特性、副产物脱气等主要问题进行全面综述,指出在工业化生产方式下,超纯净体系XLPE绝缘材料是目前用来缓解空间电荷问题和实现电缆批量化生产更为可行的技术方案,对于副产物脱气问题的研究需结合小样测试结果,向长距离批量化电缆生产的脱气工艺控制进行扩展。结合现有国内外已投运和正在规划的挤包绝缘高压直流电缆典型工程,指出未来应侧重于在提高绝缘材料电气绝缘水平的基础上,使挤包绝缘直流电缆向更高电压等级发展,并同时通过提高电缆最高允许运行温度实现更大的传输容量。此外,从提高生产效率和利于回收利用的角度考虑,可加强热塑性绝缘材料在挤包绝缘高压直流电缆中的应用研究。     

挤包绝缘高压直流电缆制造与应用中的径向梯度效应

挤包绝缘高压直流电缆在直流输电工程中应用广泛,但制造与应用中的梯度效应显著影响其直流电气性能。以500 kV交联聚乙烯直流电缆为研究对象,首先,通过仿真计算理想均匀绝缘电缆中的场强分布;然后,计算交联和脱气过程中绝缘层的温度分布,并对电缆绝缘切片取样,测量不同径向位置绝缘的相态结构和直流电气性能;最后,根据实测电导率对电缆绝缘中场强分布进行仿真。结果显示：电缆绝缘在交联和脱气过程中存在温度梯度,绝缘的相态结构和直流电气性能在径向上分布不均匀,绝缘电导率在径向上的梯度分布导致电缆绝缘中场强均呈现出内低外高的分布规律,且最外侧绝缘的场强大于均匀绝缘中的最高场强。     

Reliability improvement and economic benefits of online monitoringsystems for large induction machines

Microprocessor-based monitoring systems are being developed for the regular analysis of large induction machine variables and to predict possible fault conditions, so that preventive maintenance can be organized in a cost-effective manner. A method for the evaluation of the improvement of machine reliability made by such monitoring systems is presented. An economic and financial analysis to examine the viability of a condition monitoring system for a large machine using comprehensive rotor, stator, and other parameter measurements is developed. In two case studies, the costs of design, construction, mounting, and operation of condition monitoring systems are discussed, and estimates are made at current costs. These costs are balanced against the costs avoided in cases of unexpected machine failures, lost production, and repairs. Cost estimates for repairs and downtime are made using published information from previous reliability surveys on electrical machines. Information is presented for different machine sizes, which will indicate any relevance of the machine size when evaluating monitoring systems     

Microcomputer-Based Controls for Continuous Casting

The continuous casting of steel eliminates many processing steps, thus allowing savings in time, energy, and processing costs. In this process a moving strand of steel is partially solidified in a water-cooled mold and subsequently cooled to complete solidification by intensive-cooling water sprays. Control of the cooling sprays is complex, requiring distributed control techniques, which are not readily implemented by analog means. Therefore, digital computer control systems have been developed for this purpose. In the past these systems have used a minicomputer in a supervisory control mode to provide optimum water-flow setpoints to conventional proportional plus integral analog controllers. This approach has given satisfactory results, but initial hardware and software costs have been high, and maintenance requirements, particularly in the computer/controller interface hardware, have been excessive. US Steel is currently testing a microcomputer-based control system which has the potential for resolving these problems. This system provides all the control features normally used as well as direct digital control (ddc) of cooling water flows, thus eliminating the need for analog controllers. Experience to date indicates that this new approach will provide increased reliability along with a significant reduction in equipment and maintenance costs.     

Torque and reactive power control of a doubly fed induction machineby position sensorless scheme

A novel control strategy to realize decoupled control of torque and reactive power for a doubly excited induction machine using a position sensorless scheme is proposed. The critical issues related to the torque angle estimation and control for a doubly excited induction machine are discussed. Compared to the other position sensorless schemes for a doubly fed machine, the proposed control method uses only the rotor voltages and currents as the feedback signals, which substantially reduces the costs and enhances the reliability of the position sensorless control of a doubly fed AC machine. Computer simulation and experimental results are given to verify the position sensorless control scheme     

Rockwell控制系统在连铸机上的应用

本文介绍了Rockwell控制系统在杭钢转炉连铸机上的应用,简述了其硬件构成、下位编程软件及上位监控软件的功能等。该控制系统的应用能充分满足连铸生产自动化的要求。     

四轮水平垂直式浇铸连铸机的开发及应用

简述四轮水平垂直式浇铸连铸机的开发及应用,介绍怎样把水平浇铸和垂直浇铸两种不同形式的浇铸方式结合起来,吸取各自的优点,克服各自的缺点,形成了一种完全新式的连续铸造浇铸方式,为有色金属尤其是铝镁硅合金的连续铸造提供了有利条件,其结构简单,工艺合理,操作方便,节约材料,容易制造。     

连铸切割机监控系统

介绍了基于PLC、工业触摸屏和计算机的连铸切割机监控系统。应用三菱A985GOT触摸显示屏设计开发人机界面，实现对切割机的实时监控，并通过以太网模块QJ71E71-100实现PLC与计算机的通信，开发了计算机信息管理的应用软件。     

全浸式铜导体中拉连续退火机组性能与设计

介绍了17模铜导体中拉连续退火机组的机械及电气控制原理和设计方案。重点论述了在连续退火机组设备上所采用的新材料,新工艺,新的设计思路,突出设备的优越性和实用性。     

高压电机智能检测系统的研制

介绍了一套基于低压变频机组的高压电机检测系统,通过采用工控机为上位机、PLC为下位机,实现高压电机型式试验自动控制,对检测数据进行专家系统程序化故障判别和智能诊断,自动生成检测报告.     

一种新型的双凸极永磁电机

本文介绍一种新型双凸极永磁电机--磁通反向电机(FRM).该电机的永磁体放置在定子齿的表面,永磁体安装简单且适于高速运转;定子集中绕组中的磁通呈双极性变化,其功率密度比传统的DSPM电机要高.文中对其基本结构、工作原理及特点作了分析.     

An energy-saving overload-control technology based on a computerized training-machine system

Energy-efficient control of electric drives of an overload machine and operator training for a computerized practice-machine system (CPMS) are considered. The energy consumption of an overload machine depends on the kind of control actions taken by the operator and dynamic characteristics and modes of use of the drives, which has to do with the level of the operator’s professional training. Unreasonably abrupt accelerations and hard braking increase the wear of electromechanical equipment and lead to additional electricity consumption. The energy-saving technology of overload machine control is based on presenting the operator’s work as a functionally complete set of tasks (practice exercises) formally presented as a set of tasks for optimal electric-drive control. The solution of these tasks forms a system of wanted paths and controls used as advising actions in the practice-machine system when doing a set of practices. The results of designing a computerized simulator system (CPMS) for overload machine operators are presented. The training in this system makes it possible to form skills of energy-saving control over process equipment. The operator forms his sensory motor skills in the CPMS by doing a set of practices to simulate the actual technological operations of the overload process. The CPMS is designed to accumulate, store, and process data on the acquisition of professional skills and expertise by a trainee. The structure of the skill-formation control system is given as a component of the CPMS, and its connection with the computerized simulator (overload modeling unit) is also considered.