H级Nomex~纸绝缘干式变压器

介绍了35kV级OVDT式H级Nomex纸绝缘干式变压器的主要特点。     

H级Nomex(R)纸绝缘干式变压器

介绍了35kV级OVDT式H级Nomex^R纸绝缘干式变压器的主要特点。     

H级干式变压器的现状及其发展前景

前言 众的周知,H级干式变压器较之F级干式变压器,平均温升可以高出25％,所以设计时电流密度可以取得较高,从而可以相应缩小变压器的尺寸。此外,它还适用于温升较高的场所。浸渍式H级干式变压器的出现已经差不多是半个世纪前的事了,但是,由于在早年生产     

高海拔非包封型H级Nomex纸绝缘干式变压器

结合SG(H)10-1600／10GY实例，介绍了10kV级高海拔非包封型H级Nomex纸绝缘干式变压器的主要特点．     

H级干式变压器的现状及其发展前景

介绍了H级干式变压器的分类、NOMEX^R纸的技术性能、各类H级干式变压器的结构特点与技术性能，将H级干式变压器与环氧浇注式干式变压器进行了比较，并展望了H级干式变压器未来在我国的发展前景。     

新型结构绝缘筒在浇注干式变压器中的应用

前言 顺德特种变压器厂主要从事变压器、电抗器、组合式变电站、互感器等城网电气产品的研究开发与生产制造。干式变压器年生产能力达到300万kVA,干式电抗器年生产能力达到150kvar。 干式变压器具有以下特点:(1)安全,     

环氧浇注干式变压器绝缘综述

本文综述了国内外环氧浇注干式变压器线圈用绝缘材料,绝缘结构,浇注枝术以及设备,提出了我国环氧浇注干式变压器线圈绝缘发展方向。     

环氧树脂浇注式和NOMEX纸绝缘浸漆式干式变压器技术

介绍环氧树脂浇注式和NOMEX纸绝缘浸漆式干式变压器的技术特点，就“过载能力”和“环保特性”两个热点问题提出了观点，并从设备制造成本上进行了分析比较。     

ReliatraN H级绝缘包封型SCR9-500／10型干式变压器

昆明赛格迈电气有限公司于2001年成为杜邦^TM雷力通^TM品牌H级绝缘SCR9系列线圈包封型干式变压器在中国的特许制造商，于2003年8月成为中国变压器行业首批荣获“干式变压器Ⅰ型环境标志”产品绿色称号的企业。该公司生产的ReliatraN H级     

Hottest spot temperatures in ventilated dry type transformers

The hottest spot temperature allowance to be used for the different insulation system temperature classes is a major unknown facing IEEE Working Groups developing standards and loading guides for ventilated dry type transformers. In 1944, the hottest spot temperature allowance for ventilated dry type transformers was established as 30°C for 80°C average winding temperature rise. Since 1944, insulation temperature classes have increased to 220°C but IEEE standards continue to use a constant 30°C hottest spot temperature allowance. IEC standards use a variable hottest spot temperature allowance from 5 to 30°C. Six full size test windings were manufactured with imbedded thermocouples and 133 test runs performed to obtain temperature rise data. The test data indicated that the hottest spot temperature allowance used in IEEE standards for ventilated dry type transformers above 500 kVA is too low. This is due to the large thermal gradient from the bottom to the top of the windings caused by natural convection air flow through the cooling ducts. A constant ratio of hottest spot winding temperature rise to average winding temperature rise should be used in product standards for all insulation temperature classes. A ratio of 1.5 is suggested for ventilated dry type transformers above 500 kVA. This would increase the hottest spot temperature allowance from 30°C to 60°C and decrease the permissible average winding temperature rise from 150°C to 120°C for the 220°C insulation temperature class     

新型结构绝缘筒在浇注型干式变压器中的应用

介绍了一种新型浇注干式变压器用绝缘筒,该新型结构绝缘筒性能优良,加工简便,而且具有较大的综合经济效益。     

对干式变压器的展望

对国内干式变压器近20年来的发展情况作一简要的回顾,分析了目前产品的技术经济参数和产品的结构,结合当前国家对产品的节能和环保的要求提出了一些看法和建议。     

树脂绝缘干式变压器内部温度场的计算

树脂绝缘干式变压器内部局部温度过高会导致绝缘老化加速,大大降低变压器的使用寿命.以SC9系列一台低压箔绕单风道高压线绕无风道的树脂绝缘干式变压器为研究对象,建立了简化二维轴对称物理模型.利用该模型,通过ANSYS有限元软件仿真得到了干式变压器内部的稳态温度场.同时,还利用热路解析法,建立了干式变压器的等效热路模型.通过测量变压器表面周围空气的温度,分别对于式变压器内部的稳态温度场和暂态温度场进行了求解,并开发出基于Visual Basic的计算程序.     

浅议变压器固体绝缘的化学监督

常规化学绝缘监督方法是通过气相色谱法等手段来预测变压器内的潜伏性故障，但该方法判断变压器固体绝缘老化不准确，为此，介绍了监测固体绝缘老化的重要化学监测手段-糠醛测试，阐明测试的重要意义和方法，并结合日常工作实际提出了如何把糠醛测量有机地利用到化学预试中来。     

新型中高压电子式电压互感器

提出以微型电流互感器检测耦合电容器电流,再将电流信号传输至控制室,转换为与一次电压成正比变化的二次信号的方法构成中高压电子式电压互感器的技术方案.详细论述了新型中高压电子式电压互感器的传感原理及结构,并对耦合电容器、微型电流互感器、功率放大器等关键技术进行了讨论.对所研制的新型中高压电子式电压互感器进行了精度试验、二次短路试验,试验结果表明新型电子式电压互感器性能良好.     

油纸绝缘变压器非标准极化谱的仿真研究

针对含有局部峰值的非标准回复电压极化谱的还未能明确的诊断变压器绝缘状态,依据时域介质响应理论,结合现场回复电压测量数据,将扩展德拜模型引入介质响应等值电路,建立变压器油纸绝缘系统等值电路模型.对非标准极化谱进行仿真分析,建立非标准极化谱与等值模型参数之间的关系.仿真结果表明,各时间常数支路的变化可使极化谱产生局部峰值,而且极化谱前端的局部峰值能反映变压器绝缘油的状态情况,同时试验研究结果证明仿真结论是有效的,弥补依据非标准极化谱进行绝缘诊断的空缺.     

Electrical and chemical diagnostics of transformers insulation. B.Accelerated aged insulation samples

This paper describes the analysis of accelerated aged insulation samples to investigate the degradation processes observed in the insulation from aged power transformers. Short-term accelerated ageing experiments were performed on paper-wrapped insulated conductors and on pressboard samples. The condition of aged insulation samples was investigated by two relatively new diagnostic techniques: (a) measurements of interfacial polarization spectra by a DC method; and (b) measurements of molecular weight and its distribution by gel permeation chromatography (GPC). Several other electrical properties of the paper/pressboard samples were also studied. Possible correlations have been investigated among the different measured properties. The GPC results have been used to predict how power transformer insulation molecular weights change with temperature and time     

Background information on high temperature insulation forliquid-immersed power transformers

The availability of insulation materials having a higher temperature rating than cellulose has led to the design of high temperature power transformers for specialized applications where size and weight are important considerations. Such applications include traction transformers, mobile transformers, and power transformers with special loading requirements. Even though such equipment has been in use for many years, there are presently no standards which address high temperature materials in liquid-immersed transformers. Recognizing this deficiency, the IEEE Transformers Committee has established a Working Group to investigate what standards or guides could be formulated. As a first step, the Working Group has prepared this “state-of-the-art” paper to document background information on the materials and their application. It is hoped that discussion of this paper will help to establish future directions for standards     

油纸绝缘变压器介质响应极化谱的探索与研究

基于扩展德拜模型,建立油纸绝缘变压器绝缘状态与介质响应等值电路之间的关系,并仿真分析模型(时间常数、支路数)改变引起回复电压特征参数和极化谱的变化规律。仿真分析结果表明,极化谱回复电压峰值与主时间常数可作为变压器绝缘诊断的判据,且时间常数不同的RC支路在回复电压极化谱的对应区段才有所影响。通过研究多台不同绝缘状态的变压器,总结出绝缘老化程度与支路数取值的内在联系,由此获取的等值参数最优,所建立模型与变压器实际状况相吻合,可作为油纸绝缘系统状态准确诊断和研究的基础。