双母线供电倒母线操作方法

双母线供电的高压开关柜,系统接线结构复杂,检修倒闸操作量大、操作安全风险高,阐述实践中的双母线供电倒母线操作方法,能防止隔离开关倒母线误操作事故的发生,确保操作安全可靠,满足生产要求。     

电气工程公共直流母线桥的转化设计

传统的母线桥一般用于远距离供电,需要在顶壁做吊攀,设计和施工相对比较复杂,而用于短距离供电时成本则相对比较高。随着半导体功率器件的发展,以公共直流母线系统为主的多电动机传动变频调速的应用越来越广泛。在对这种多电动机传动变频调速系统的设计中,为了充分利用整流单元的供电效率、满足生产工艺要求、降低投资成本,通常采取增加公共直流母线供电的变频调速控制柜的数量以满足要求。本文通过对东方特钢公共直流母线改造设计的研究,提出了一种用于公共直流母线的侧挂式直流母线桥设计方法,应用后取得良好的应用效果。     

10kV不完全母线差动保护的应用分析

10～35kV母线作为用户负荷供电电源端,在供电、配电环节承担至关重要的作用,因此提出在变电站特别是大型厂矿的总降压站装设中低压母线专用保护的必要性和可行性,并提出了方向过流闭锁不完全母差保护的方案和优缺点。     

电气联锁技术在济钢2×90m^2烧结机低压供电系统中的应用

利用电气联锁技术，完善了济钢２×９０ｍ＾２烧结机低压供电系统内在电气性能，确保了“分段环形母线”供电系统分段供电互为备用、灵活组合，防止了受电柜井联运行，从而提高了系统整体技术水平和安全可靠性。     

变电站10 kV系统单相接地引起的短路故障分析

针对系统发生单相接地时很容易产生间歇性弧光过电压从而造成短路事故的问题,提出了对容量不足的消弧线圈进行扩容、合理布置消弧线圈的分布、制定10 kV母线并列操作时消弧线圈控制器的控制方式,使炼钢站10 kV系统运行参数得到优化,在任何运行方式下都能及时补偿电容电流,进而提高炼钢站10 kV系统供电可靠性。     

直流对地电压高于母线电压1／2的原因分析及解除方法

1　简介80年代以来,镉镍电池屏在电力系统的使用量逐渐增加。由于镉镍电池的容量通常比较小,为确保可靠的直流电源,一些重要的变电所采取两套直流屏分列运行对直流负荷供电,且两套直流屏可互为备用。在我厂某变电所值班人员检测直流母线绝缘情况时,发现两套220V直流屏都出现了母线对地电压为330V的现象。这种现象未曾出现过,因此,我们先从理论上进行了分析研究,然后通过实验验证了其正确性。2　原因分析单套直流电源(220V)运行时,从接地装置图1中分析。无论如何不应该出现对地电压330V的情况。两套直流电源分列运行才可能出现这种现象,即…     

自备电站主6kV母线保护的改进建议

通过分析现行自备电站主6kV母线保护配置，提出了该保护装置在工作母线倒至备用母线运行时的改进建议，以及配合母线倒运时母线差动保护切换的方法。     

冶金自备电厂低电压停机问题分析及对策

分析了近年某冶金自备电厂所发生的一起电网低电压停机问题,从故障现象及后续工况变化出发,确定该起停机故障与电压暂降之间的关系,主要原因为冶金行业工作特性引发的局部冲击性电流,使自备电厂联络母线的供电电压出现相应波动,导致变频器等电压敏感元件退出运行,继而导致整机停运。提出了针对性工程实用解决方法。     

铝电解槽不停槽端头母线改造

本文介绍了铝电解槽不停电情况下槽周母线的改造方法,使电解槽系列在不停产的情况下进行母线改造,改善了电解槽的磁场条件和电解槽的运行环境,提高了电解槽运行的稳定性,降低能耗。     

铝电解槽短路口爆炸后的母线连接技术及不停电修补技术

针对300kA电解槽短路口爆炸事故,采取母线连接技术,用最短时间隔离事故槽,恢复系列供电,保证正常生产,将损失降至最低;文章还介绍了经过反复试验、探索出的一种不需要系列停电、在电解现场修复损坏立柱母线短路口的技术。     

熔炼次数对M17返回料合金成分、组织和性能的影响

实验结果表明,M17铸造高温合金(%:0.16C、8.79Cr、5.79A1、4.93Ti、3.29Mo、15.20Co、0.78V、0.015B、0.073Zr、0.002S、0.001P、0.001 1O、0.001 0N)经25 kg真空感应炉返回重熔后,Si含量随重熔次数的增加而略有增加,合金中主要元素和其它杂质元素S、P、H的含量变化不大,而氧、氮略有增加;合金中初生碳化物由新合金中的草书体逐渐向返回合金块状转变,初生碳化物的遗传性堵塞合金凝固时的补缩通道,使返回料合金的疏松倾向增大,高温塑性下降较大。     

China's Major Non-ferrous Metals Imports & Exports

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Zinc Production by Province in 2014

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80% of Chinese Firms Purchasing Overseas Mines Ended up in the Red

<正>Minmetals Resources acquired the world’s largest copper mine under construction for USD5.85 billion.One after another,listed companies Jien Nickle,China Molybdenum and Chihong Zinc and Germanium raised money to get involved in overseas mining projects…SOEs and private enterprises are engaged in a frenzy of overseas mine purchasing.A reporter with Economic     

Copper Processing Profit Dropped Sharply,Copper Consumption Will Face Impact in the Second Half of the Year

正Judging from China’s copper consumption field,the biggest consumption unit is electric power,which accounts for 47%of total consumption;it is followed by light industry sector,including household electrical appliance,machinery,durable goods and hardware etc,which accounts for 22%of total consumption;followed by transportation field,     

Central Geological Prospecting Fund Newly Added 16.47 Million Tonnes of Bauxite in 2013

正In 2013,the Central Geological Prospecting Fund(CGPF)Project newly discovered 15 ore fields,including 3 large above ore fields,and 5medium sized ore fields.The reporter learned from the recently published"Annual Report of Central Geological Prospecting Fund Project(2013)"that,from 2006 to 2013 the CGPF     

Manufacturers of Copper Tube for Central Air Conditioner Use Face Mounting Pressure in the Final Quarter of the Year

正This year,the investment growth rate of real estate industry continued to slow down,sold area of commercial housing also dropped significantly,which brought huge pressure to the domestic air conditioning manufactures.In the first half of the year,by relying on high growth in national financial expenditure,along with investment in public infrastructure     

Xinjiang Ranks No.1 in Production of Primary Aluminum in China

正Kang Yi,Honorary Chairman of China Nonferrous Metals Industry Association,said recently at the Forum on Development of the Non-ferrous Metals Industry in Central and Western China held in Zhengzhou that,as more and more electrolytic aluminum factories in Xinjiang came into operation,the electrolytic aluminum output of Xinjiang had reached2,275,000 tons in the first 7 months this year,     

Shenhuo Coal Industry and Electricity Power Completed800,000 t/a Aluminum Project in Xinjiang

正"Xinjiang project has been completed according to schedule,but total completion and total start of production are two different concepts,after completion it still needs a gradual process of reaching production target."On the morning of November 3,Shenhuo Coal Industry and Electricity Power told investors the above statement on the investor interaction platform.     

Guangdong Metal Transaction Center has Become the Second Largest Precious Metal Transaction Platform Nationwide

正The reporter learned from Guangdong Province Precious Metal Transaction Center that in 2013the Center maintained healthy development momentum,and had become the second largest precious metal transaction platform in China in terms of market size;currently Guangdong is quickening steps of financial innovation for the Center,aiming to build a transaction center with international core competitiveness.