
本人主要对下面问题有不同观点:1、所称的“总等电位联结系统”不适用于建筑物电气装置,因为不现实,在IEC60364系列标准中找不到其应用,有的只是总等位联结和保护等电位联结,不单是术语不同,关键是赋于他们的作用是不同的。2、由于条件很不同电力系统自用电装置可以采用“总等电位联结接地系统”,EPR=2000V也可以。3、对变压器低压侧中性点接地电阻值的计算观点也不同,虽然都是引自IEC标准,但理解不同,结论也就不同了,这很正常,公开交流,有助于接地规范的完善。
本文介绍了光电电流互感器的结构原理和输出特点,提出了光电电流互感器的测试和校验方法,对光电互感器基于比对技术和采用ES光电互感器校验仪来完成对电子式电流互感器的校验做了全面的介绍.
A quick method of calculating short-circuit current is deduced by theory in this paper.The result of it is compaired with that of PSASP method,and it is showed the accuracy of the quick method is not as good as PSASP method.However,it is suitable for power network planning with the easy fomula,saving time.The impact of substation reformation to every node short-circuit current is analysed,so as to be intended to give a guide effect to power network planning.
The wiring pinciple and technique parameters of high-speed current limiting protection switch are presented.The breaking performance of high-speed current limiting protection switch and circuit breaker are analyzed and compared.Several application schemes are also given.
Based on the characteristics of large plant area and high power consumption of street lamp lighting,the article adopts technical measures of intelligent regulated power electrical lighting,achieves obvious energy saving effect that average power saving ratio is up to 33%,decreases lamp wastage,attains the purpose of energy saving,cost reduction and efficiency improving.
It is a scholar-concerned problem that how to reduce energy-loss when conducting the release testing in order to get the data required.A new type of tester,which adopt the frequency-convertor and speed-regulation technology to carry through diversified motor experiments,besides convert the AC power to DC bus,and simulate or decelerate the drive and load process of the increaser and reducer by controlling the corresponded frequency convert.The Internet-control technology based on PLC is adopted,so as to equip the system with excellent practicality and operability.
变压器的运行状态直接影响电力系统的安全性,开展变压器的在线故障诊断研究,可以尽早发现变压器的潜伏性故障,对提高变压器的运行维护水平,具有重要的意义。本文首先阐述了变压器在线故障诊断的意义,然后对变压器的故障类型和故障诊断方法做了详细的介绍,最后系统地阐述了基于神经网络的变压器诊断理论。
超高压变电站二次系统中微电子设备的保护,虽然已经得到了关注,但还没有形成体系。该文对目前变电站微电子设备遭受干扰源和干扰途径进行了理论分析,并根据南方超高压变电站微电子保护环境,运用软件ATP建立了模型,最后针对目前微电子防护现状,提出了新的改进措施,为完善电子设备保护提供了新思路。
发电机是风力发电系统中重要的部件,因工作内特殊性在结构上及并网技术上与普通发电机略有不同.本文就风力发电系统中目前常见的几种异步发电机型及其并网技术作简单介绍.
THB1系列小型断路器广泛地用于建筑及类似场所的电力线路设施和电气设备进行过电流保护,亦可用于不频繁的通断操作。产品具有较高的短路分断能力及良好的限流技术性能,本文介绍了THB1小型断路器采用的限流技术,如U型触头系统、优化电弧分割的灭弧装置、气吹灭弧和双断点变电阻熄弧等概念。
<正>电气安全防护是汲及人身及设备安全的重要举措,但从目前各类防护措施看,存在较多问题,有的无法取得安全预警信号或安全措施不到位;有的虽有保护装置,但对某些事故却无能为力,笔者就上述有关安全问题谈谈看法以期引起注意,以便在今后
本文针对导致高频保护通道异常的常见原因进行了分析和总结,同时提出了相应的处理方法,提高维护高频保护通道的水平,确保电网安全运行。
本文主要介绍无功补偿回路串联电抗器防止谐振的工作原理,并计算了串联不同电抗率对应谐振频率、电容器两端电压升高倍数以及实际无功补偿容量增加的倍数。
等电位联结端子(PE线)、外部可导电部分和外露可导电部分是等电位联结的三类基本要素。本文从该三类要素着手,系统梳理了各要素及各要素之间所做的等电位联结的作用和重要性,提出了全新的"辅助等电位联结"和"主等电位联结"分类定义,构造了新的等电位联结分类方案。在此基础上,分析了目前等电位联结应用存在的误区,并对目前等电位联结做法提出了实质性的改进意见。
1 风力发电机组安全保护系统 风力发电机组安全保护系统分为三个层次:(1)计算机(电脑)系统的保护.如电网电压过高或过低、风速过快或过慢、扭缆达到定值等外界因素出现时,计算机电控系统立即发出指令使机组退网停机.
Through the analysis of the mechanism about inrush current of Transformer,a new method,wavelet analysis,is applied to distinguish the inrush current and improve the transformer differential protection against the impact on of inrush current. By MATLAB simulation,the results show that the method eimprove the accuracy of distinguishing inrush current and has good application prospect and value.