• 全国统一服务热线:0577- 62852666

格亚继电器,13年匠心智造!

位置: 全天购彩计划,购彩网全天24小时计划  >  新闻资讯  >  继电保护的要求、原理及几种继电器构成

继电保护的要求、原理及几种继电器构成

2017-06-02 15:56:00 字号: 分享

继电保护的基本知识

一、继电保护的任务和要求

1.继电(dian)保(bao)护的任务

为保证供(gong)(gong)配(pei)(pei)电(dian)(dian)系统(tong)的(de)安全(quan)运行,避免过(guo)负(fu)荷和(he)短路(lu)引起的(de)过(guo)电(dian)(dian)流(liu)对系统(tong)的(de)影响,在供(gong)(gong)配(pei)(pei)电(dian)(dian)系统(tong)中要装有不同类型(xing)的(de)过(guo)电(dian)(dian)流(liu)保护(hu)装置(zhi)。常用(yong)的(de)过(guo)电(dian)(dian)流(liu)保护(hu)装置(zhi)有熔断器(qi)保护(hu)、低压断路(lu)器(qi)保护(hu)和(he)继(ji)电(dian)(dian)保护(hu)。其中继(ji)电(dian)(dian)保护(hu)广泛应用(yong)于高(gao)压供(gong)(gong)配(pei)(pei)电(dian)(dian)系统(tong)中,其保护(hu)功能很多,而且是实现供(gong)(gong)配(pei)(pei)电(dian)(dian)自动化的(de)基础。

继电保护装置(zhi)是(shi)指能反映供配电系统中电气设备发(fa)生的(de)故障或不正常(chang)工(gong)作状态,并能动(dong)(dong)作于断(duan)路(lu)器(qi)跳(tiao)闸或起动(dong)(dong)信号装置(zhi)发(fa)出预(yu)报信号的(de)一种(zhong)自动(dong)(dong)装置(zhi)。

继电保护的主(zhu)要任务如下:

(1)自动、迅速(su)、有选择(ze)性地将(jiang)故障元件从供配(pei)电系统切除,使其(qi)他非故障部分(fen)迅速(su)恢复正常供电;

(2)能正确(que)反(fan)映(ying)电(dian)气设备(bei)的不(bu)正常运行状态,发出预报信号(hao),以便操(cao)作人(ren)员采取措(cuo)施,恢复电(dian)气设备(bei)正常工作;

(3)与(yu)供(gong)配电(dian)(dian)系(xi)统(tong)的自(zi)动装置(如(ru)自(zi)动重合(he)闸(zha)装置、备用(yong)电(dian)(dian)源自(zi)动投入装置等(deng))配合(he),提高(gao)供(gong)电(dian)(dian)系(xi)统(tong)的运行可靠性。

建筑供配电系统继(ji)电保(bao)护的(de)(de)特点是简单(dan)、有(you)效、可靠,且有(you)较(jiao)强的(de)(de)抗(kang)干扰能力。

2.对继电保护的基本要(yao)求

继电保护的(de)设计应以合理的(de)运行方式(shi)和可能的(de)故(gu)障(zhang)类型为(wei)依据,并应满足选择性、速动性、可靠性、灵敏性四(si)项(xiang)基本要求(qiu)。

(1)选(xuan)择性

选择(ze)性是(shi)指(zhi)首先由(you)故(gu)(gu)障设备或(huo)线路本身的(de)保(bao)护(hu)切(qie)除(chu)故(gu)(gu)障。当供电(dian)系统(tong)发生短路故(gu)(gu)障时,继(ji)电(dian)保(bao)护(hu)装置动作,只切(qie)除(chu)故(gu)(gu)障元(yuan)件(jian),并使停电(dian)范围最(zui)小,以减小故(gu)(gu)障停电(dian)造(zao)成(cheng)的(de)影(ying)响。保(bao)护(hu)装置这种(zhong)能挑选故(gu)(gu)障元(yuan)件(jian)的(de)能力称(cheng)为保(bao)护(hu)的(de)选择(ze)性。

(2)速动性

为(wei)了减(jian)小由于故(gu)(gu)障(zhang)(zhang)引起(qi)的(de)(de)(de)损(sun)失,减(jian)少(shao)用户在(zai)故(gu)(gu)障(zhang)(zhang)时(shi)低电压下的(de)(de)(de)工作时(shi)间,以(yi)及提(ti)高电力系(xi)统运行的(de)(de)(de)稳定性(xing),要求(qiu)继电保护装置(zhi)在(zai)发生故(gu)(gu)障(zhang)(zhang)时(shi)尽快动作并将故(gu)(gu)障(zhang)(zhang)切(qie)除(chu)。快速地切(qie)除(chu)故(gu)(gu)障(zhang)(zhang)部分可(ke)以(yi)防止(zhi)故(gu)(gu)障(zhang)(zhang)扩大,减(jian)轻故(gu)(gu)障(zhang)(zhang)电流对电气设备(bei)的(de)(de)(de)损(sun)坏程度,加快供(gong)电系(xi)统电压的(de)(de)(de)恢复(fu),提(ti)高供(gong)电系(xi)统运行的(de)(de)(de)可(ke)靠(kao)性(xing)。

(3)可靠性(xing)

可(ke)靠性(xing)是指保(bao)护(hu)(hu)装置(zhi)应该(gai)动(dong)(dong)作时动(dong)(dong)作,不应该(gai)动(dong)(dong)作时不动(dong)(dong)作。为(wei)保(bao)证可(ke)靠性(xing),宜选用尽可(ke)能简(jian)单的(de)保(bao)护(hu)(hu)方(fang)式,采用可(ke)靠的(de)元(yuan)件和(he)尽可(ke)能简(jian)单的(de)回路(lu)构成性(xing)能良好(hao)的(de)装置(zhi),并应有必(bi)要的(de)检测、闭锁和(he)双(shuang)重化等措施(shi)。保(bao)护(hu)(hu)装置(zhi)应便(bian)于整定、调试和(he)运行维护(hu)(hu)。

(4)灵敏(min)性

灵敏(min)性是指继电保护(hu)(hu)在(zai)其保护(hu)(hu)范围内对发(fa)生故(gu)障或(huo)不正常工作状(zhuang)态时(shi)的(de)(de)反应能力(li)(li)。过电流保护(hu)(hu)的(de)(de)灵敏(min)度SP用其保护(hu)(hu)区内在(zai)电力(li)(li)系统为最小运行方(fang)式时(shi)的(de)(de)最小短(duan)路(lu)电流Ik,min与保护(hu)(hu)装置一(yi)次(ci)动作电流,即(ji)保护(hu)(hu)装置动作电流换算(suan)到一(yi)次(ci)电路(lu)的(de)(de)值,OP,1的(de)(de)比值来表示,即(ji)SP=Ik,min/IOP,1

对不同(tong)(tong)作用的保护装(zhuang)置(zhi)和被保护设(she)(she)备,所要求的灵敏(min)度是不同(tong)(tong)的,在《电力(li)装(zhuang)置(zhi)的继电保护和自动(dong)装(zhuang)置(zhi)设(she)(she)计技术规范》(GB50062;1992)中都有规定(ding)。

另外(wai),上述介绍的(de)四项基本要(yao)求对(dui)(dui)于一(yi)个具体的(de)保护装(zhuang)置(zhi)不一(yi)定都是同等重(zhong)要(yao)的(de),而应有(you)所侧重(zhong)。例(li)如,电(dian)力(li)变(bian)压器是供配电(dian)系统中最关(guan)键(jian)的(de)设备,对(dui)(dui)其保护装(zhuang)置(zhi)的(de)灵敏度(du)要(yao)求较(jiao)高;而对(dui)(dui)一(yi)般(ban)电(dian)力(li)线路的(de)保护装(zhuang)置(zhi),就要(yao)求其选择性较(jiao)高。

二、继电保护的基本原理

电(dian)(dian)(dian)力(li)(li)系(xi)统发生故障时(shi)会引起电(dian)(dian)(dian)流(liu)的增(zeng)(zeng)加(jia)、电(dian)(dian)(dian)压的降低(di)以及电(dian)(dian)(dian)流(liu)与电(dian)(dian)(dian)压间相(xiang)位的变化,因此,电(dian)(dian)(dian)力(li)(li)系(xi)统中所采(cai)用的各(ge)种继电(dian)(dian)(dian)保护(hu)大(da)多数(shu)是利用故障时(shi)物理量(liang)与正常运行时(shi)物理量(liang)的差别(bie)来构成的,例如,反映(ying)电(dian)(dian)(dian)流(liu)增(zeng)(zeng)大(da)的过电(dian)(dian)(dian)流(liu)保护(hu)、反映(ying)电(dian)(dian)(dian)压降低(di)(或升高)的低(di)电(dian)(dian)(dian)压(或过电(dian)(dian)(dian)压)保护(hu)等。

继(ji)电(dian)保(bao)护(hu)原(yuan)理(li)结构方框图如图1所示。它由(you)三部(bu)(bu)(bu)分(fen)组(zu)(zu)成(cheng),(1)测量(liang)部(bu)(bu)(bu)分(fen);;用来测量(liang)被保(bao)护(hu)设备(bei)输入的有关信(xin)号(hao)(电(dian)流、电(dian)压)等,并(bing)和已给定的整定值进行(xing)比较(jiao)判断是否应该(gai)起动;(2)逻(luo)辑部(bu)(bu)(bu)分(fen);;根(gen)据测量(liang)部(bu)(bu)(bu)分(fen)各输出量(liang)的大(da)小(xiao)、性质及其组(zu)(zu)合或(huo)输出顺序,使保(bao)护(hu)装置按(an)照一定的逻(luo)辑程序工作,并(bing)将信(xin)号(hao)传输给执行(xing)部(bu)(bu)(bu)分(fen);(3)执行(xing)部(bu)(bu)(bu)分(fen);;根(gen)据逻(luo)辑部(bu)(bu)(bu)分(fen)传输的信(xin)号(hao),最后完成(cheng)保(bao)护(hu)装置所负担的任务,给出跳(tiao)闸或(huo)信(xin)号(hao)脉冲。

如图2所示(shi)为线(xian)路(lu)(lu)过电(dian)(dian)流保(bao)(bao)护(hu)基(ji)本(ben)(ben)原理(li)示(shi)意(yi)图,用以说明(ming)继(ji)电(dian)(dian)保(bao)(bao)护(hu)的(de)(de)(de)(de)组(zu)成和(he)基(ji)本(ben)(ben)原理(li)。图2中(zhong)(zhong),电(dian)(dian)流继(ji)电(dian)(dian)器(qi)(qi)KA的(de)(de)(de)(de)线(xian)圈(quan)接(jie)于(yu)(yu)被(bei)保(bao)(bao)护(hu)线(xian)路(lu)(lu)电(dian)(dian)流互感器(qi)(qi)TA的(de)(de)(de)(de)二(er)次回路(lu)(lu),即保(bao)(bao)护(hu)的(de)(de)(de)(de)测量(liang)回路(lu)(lu),它(ta)监视被(bei)保(bao)(bao)护(hu)线(xian)路(lu)(lu)的(de)(de)(de)(de)运(yun)行状态,测量(liang)线(xian)路(lu)(lu)中(zhong)(zhong)电(dian)(dian)流的(de)(de)(de)(de)大小。在正常运(yun)行情(qing)况下,当(dang)(dang)线(xian)路(lu)(lu)中(zhong)(zhong)通(tong)(tong)过最大负(fu)荷电(dian)(dian)流时(shi)(shi)(shi),继(ji)电(dian)(dian)器(qi)(qi)不动作(zuo)(zuo);当(dang)(dang)被(bei)保(bao)(bao)护(hu)线(xian)路(lu)(lu)K点(dian)发生(sheng)短(duan)路(lu)(lu)时(shi)(shi)(shi),线(xian)路(lu)(lu)上的(de)(de)(de)(de)电(dian)(dian)流突然(ran)增(zeng)大,电(dian)(dian)流互感器(qi)(qi)TA二(er)次侧(ce)的(de)(de)(de)(de)电(dian)(dian)流也按变比相应增(zeng)大,当(dang)(dang)通(tong)(tong)过电(dian)(dian)流继(ji)电(dian)(dian)器(qi)(qi)KA的(de)(de)(de)(de)电(dian)(dian)流大于(yu)(yu)其整定(ding)值(zhi)时(shi)(shi)(shi),继(ji)电(dian)(dian)器(qi)(qi)立即动作(zuo)(zuo),触点(dian)闭(bi)合,接(jie)通(tong)(tong)逻辑(ji)电(dian)(dian)路(lu)(lu)中(zhong)(zhong)时(shi)(shi)(shi)间(jian)(jian)继(ji)电(dian)(dian)器(qi)(qi)KT的(de)(de)(de)(de)线(xian)圈(quan)回路(lu)(lu),时(shi)(shi)(shi)间(jian)(jian)继(ji)电(dian)(dian)器(qi)(qi)起(qi)动并根据短(duan)路(lu)(lu)故障(zhang)持续的(de)(de)(de)(de)时(shi)(shi)(shi)间(jian)(jian)作(zuo)(zuo)出(chu)保(bao)(bao)护(hu)动作(zuo)(zuo)的(de)(de)(de)(de)逻辑(ji)判断(duan)(duan),时(shi)(shi)(shi)间(jian)(jian)继(ji)电(dian)(dian)器(qi)(qi)KT动作(zuo)(zuo),其延时(shi)(shi)(shi)触点(dian)闭(bi)合,接(jie)通(tong)(tong)执行回路(lu)(lu)中(zhong)(zhong)的(de)(de)(de)(de)信(xin)号继(ji)电(dian)(dian)器(qi)(qi)KS和(he)断(duan)(duan)路(lu)(lu)器(qi)(qi)QF的(de)(de)(de)(de)跳闸线(xian)圈(quan)回路(lu)(lu),使(shi)断(duan)(duan)路(lu)(lu)器(qi)(qi)跳闸,切(qie)除短(duan)路(lu)(lu)故障(zhang)。

三、断电器的构成和分类

1.继电器的作用

继电(dian)器是(shi)一种在其输(shu)入的物理量(电(dian)气量或非电(dian)气量)达到(dao)规定值时,其电(dian)气输(shu)出电(dian)路被接通或分断的自动电(dian)器。

继(ji)电器一般(ban)由感受元(yuan)件(jian)、比较元(yuan)件(jian)和执行元(yuan)件(jian)三个主要部分组成(cheng)。

(1)感(gan)受(shou)元件将感(gan)受(shou)到(dao)的(de)物理量(如电流、电压)的(de)变化情况(kuang)综(zong)合(he)后(hou)送到(dao)比较(jiao)元件。

(2)比(bi)较(jiao)元(yuan)件将感受元(yuan)件送(song)来的(de)物理(li)(li)量(liang)与预先给定的(de)物理(li)(li)量(liang)(整定值)相比(bi)较(jiao),根据比(bi)较(jiao)的(de)结果(guo)向(xiang)执行元(yuan)件发出指令。

(3)执行(xing)元(yuan)件(jian)根据来自比较元(yuan)件(jian)的指令自动完成继(ji)电器所担负的任(ren)务,例如向(xiang)断路器发(fa)出跳闸(zha)脉(mai)冲(chong)或进行(xing)其他(ta)操作。

2.继电器的(de)分(fen)类

继电器(qi)的种类很多,目前一(yi)般分类方法如下:

(1)按继电(dian)器(qi)动作(zuo)和构(gou)成原理可分为(wei)电(dian)磁(ci)型(xing)(xing)(xing)、感应型(xing)(xing)(xing)、整流型(xing)(xing)(xing)、极化(hua)型(xing)(xing)(xing)、半导体型(xing)(xing)(xing)、热力(li)型(xing)(xing)(xing)等继电(dian)器(qi)。

(2)按(an)照继电(dian)器反(fan)映(ying)物(wu)理量的性质可(ke)分为电(dian)流、电(dian)压、时间(jian)、信号、功(gong)率、方(fang)向、阻(zu)抗、频率等继电(dian)器。

继(ji)电(dian)(dian)器(qi)又可分为反映电(dian)(dian)气(qi)量增加和反映电(dian)(dian)气(qi)量减少(shao)两大类。前者(zhe)(zhe)为过量继(ji)电(dian)(dian)器(qi),如过电(dian)(dian)流(liu)继(ji)电(dian)(dian)器(qi)等,后者(zhe)(zhe)为欠量继(ji)电(dian)(dian)器(qi),如欠电(dian)(dian)压(ya)继(ji)电(dian)(dian)器(qi)等。

除此之外,还有一(yi)类反映(ying)非(fei)电气(qi)(qi)量参数(shu)而动作的(de)继电器,如(ru)气(qi)(qi)体,瓦(wa)斯,继电器、温度继电器等。

3.继电(dian)器(qi)的(de)表示方法

我国继(ji)电(dian)器型(xing)号(hao)(hao)的(de)编制是(shi)以(yi)汉语拼音字母表(biao)示(shi)的(de),由动作原理代(dai)号(hao)(hao)、主(zhu)要功(gong)能代(dai)号(hao)(hao)、设计序(xu)号(hao)(hao)及(ji)主(zhu)要规格代(dai)号(hao)(hao)所组成,其(qi)表(biao)示(shi)形式如下(xia):

设计序号及主(zhu)要规(gui)格用(yong)(yong)阿拉伯数(shu)(shu)字(zi)表(biao)示(shi),继电(dian)器的主(zhu)要规(gui)格代号常(chang)用(yong)(yong)来表(biao)示(shi)触点的形(xing)式及数(shu)(shu)量(liang)。例(li)如,DL-11/10表(biao)示(shi)电(dian)磁型电(dian)流继电(dian)器,其(qi)中第(di)一(yi)(yi)个(ge)数(shu)(shu)字(zi)"1"表(biao)示(shi)设计序号(10系列),第(di)二个(ge)"1"表(biao)示(shi)有一(yi)(yi)对动(dong)合触点,

"10"表示最大动作电流为10A。

4.常用继电器

35kV及以下电(dian)力(li)网中的电(dian)力(li)线路和(he)电(dian)气(qi)设(she)备继电(dian)保护(hu)装置(包括供电(dian)系统(tong)),除了(le)日渐推广的微机保护(hu)外(wai),仍(reng)大量采用电(dian)磁型和(he)感应型继电(dian)器。下面重点介绍几种反映(ying)单一(yi)电(dian)气(qi)量的电(dian)磁型继电(dian)器的结(jie)构、原理及特性。

(1)电(dian)磁式(shi)电(dian)流(liu)继电(dian)器

电(dian)磁式电(dian)流继(ji)电(dian)器在继(ji)电(dian)保护(hu)装置中作(zuo)为起动元件(jian),如图3所示为DL系列(lie)电(dian)磁式电(dian)流继(ji)电(dian)器的内部结构和(he)内部接(jie)线图。

电磁式(shi)电流(liu)继电器的工(gong)作(zuo)原理(li)如下,当线圈2通(tong)过电流(liu)IKA时,电磁力(li)矩(ju)(ju)M1试图使(shi)可(ke)动(dong)舌(she)片(pian)3向(xiang)顺时针方向(xiang)旋转。在(zai)正常工(gong)作(zuo)时,由于IKA较(jiao)小(xiao),其所(suo)产(chan)生的电磁力(li)矩(ju)(ju)不(bu)(bu)足以克服弹簧4的反(fan)抗力(li)矩(ju)(ju)M2,故舌(she)片(pian)3不(bu)(bu)会转动(dong),不(bu)(bu)会带动(dong)可(ke)动(dong)触点5与(yu)静(jing)触点6闭(bi)合(he);在(zai)短路故障时,IKA将(jiang)大大增加,M1>M2,使(shi)舌(she)片(pian)3转动(dong),带动(dong)可(ke)动(dong)触点5与(yu)静(jing)触点6接(jie)触而使(shi)其闭(bi)合(he)。

能(neng)使(shi)(shi)过电(dian)(dian)(dian)(dian)(dian)流(liu)(liu)继电(dian)(dian)(dian)(dian)(dian)器(qi)刚好(hao)动(dong)作(zuo)并使(shi)(shi)触点(dian)(dian)闭(bi)合(he)的(de)电(dian)(dian)(dian)(dian)(dian)流(liu)(liu)IKA值(zhi)称(cheng)为(wei)该(gai)继电(dian)(dian)(dian)(dian)(dian)器(qi)的(de)动(dong)作(zuo)电(dian)(dian)(dian)(dian)(dian)流(liu)(liu),用IOP表示(shi)。在继电(dian)(dian)(dian)(dian)(dian)器(qi)动(dong)作(zuo)后,逐渐(jian)减(jian)小(xiao)IKA。当继电(dian)(dian)(dian)(dian)(dian)器(qi)刚好(hao)返回(hui)到原始位置时(shi)所对(dui)应的(de)IKA值(zhi)称(cheng)为(wei)返回(hui)电(dian)(dian)(dian)(dian)(dian)流(liu)(liu),用Ire表示(shi)。上述定义(yi)还(hai)可以(yi)说(shuo)成,使(shi)(shi)继电(dian)(dian)(dian)(dian)(dian)器(qi)常开(kai)(kai)接点(dian)(dian)闭(bi)合(he)的(de)最小(xiao)电(dian)(dian)(dian)(dian)(dian)流(liu)(liu)称(cheng)为(wei)动(dong)作(zuo)电(dian)(dian)(dian)(dian)(dian)流(liu)(liu)IOP;使(shi)(shi)继电(dian)(dian)(dian)(dian)(dian)器(qi)闭(bi)合(he)的(de)常开(kai)(kai)触点(dian)(dian)断开(kai)(kai)的(de)最大电(dian)(dian)(dian)(dian)(dian)流(liu)(liu)称(cheng)为(wei)返回(hui)电(dian)(dian)(dian)(dian)(dian)流(liu)(liu)Ire。继电(dian)(dian)(dian)(dian)(dian)器(qi)的(de)返回(hui)电(dian)(dian)(dian)(dian)(dian)流(liu)(liu)Ire与(yu)其动(dong)作(zuo)电(dian)(dian)(dian)(dian)(dian)流(liu)(liu)IOP的(de)比值(zhi)称(cheng)为(wei)返回(hui)系数Kre(其值(zhi)一般小(xiao)于1),即Kre=Ire/IO

(2)电磁式电压(ya)继电器

电(dian)(dian)(dian)(dian)磁式(shi)电(dian)(dian)(dian)(dian)压继(ji)电(dian)(dian)(dian)(dian)器(qi)的结构、工作原(yuan)理(li)与电(dian)(dian)(dian)(dian)磁式(shi)电(dian)(dian)(dian)(dian)流继(ji)电(dian)(dian)(dian)(dian)器(qi)基本相(xiang)同(tong)(tong)。不同(tong)(tong)之处(chu)是,电(dian)(dian)(dian)(dian)压继(ji)电(dian)(dian)(dian)(dian)器(qi)的线(xian)圈(quan)是电(dian)(dian)(dian)(dian)压线(xian)圈(quan),其(qi)匝数多而线(xian)径(jing)细,而电(dian)(dian)(dian)(dian)流继(ji)电(dian)(dian)(dian)(dian)器(qi)的线(xian)圈(quan)为电(dian)(dian)(dian)(dian)流线(xian)圈(quan),其(qi)匝数少而线(xian)径(jing)粗(cu)。

电(dian)磁式电(dian)压继电(dian)器(qi)有过电(dian)压和欠电(dian)压两大(da)类(lei),其中欠电(dian)压继电(dian)器(qi)在(zai)工厂供电(dian)系统应用较多

类似过电(dian)流继电(dian)器,欠电(dian)压(ya)(ya)继电(dian)器的动(dong)(dong)(dong)作(zuo)(zuo)电(dian)压(ya)(ya)UOP是使其动(dong)(dong)(dong)作(zuo)(zuo)的最(zui)大(da)电(dian)压(ya)(ya),而它的返回(hui)(hui)电(dian)压(ya)(ya)Ure是使其返回(hui)(hui)的最(zui)小电(dian)压(ya)(ya),返回(hui)(hui)系数(shu)Kre=Ure/UOP。由于欠电(dian)压(ya)(ya)继电(dian)器的返回(hui)(hui)电(dian)压(ya)(ya)Ure大(da)于动(dong)(dong)(dong)作(zuo)(zuo)电(dian)压(ya)(ya)UOP,所(suo)以其返回(hui)(hui)系数(shu)Kre>1,一般为(wei)1~1.2。

(3)电(dian)磁式时间继电(dian)器

时间继(ji)电器(qi)在保护装置(zhi)中起延时作(zuo)用(yong),以保证(zheng)保护装置(zhi)动(dong)作(zuo)的选择性(xing)。

DS系列电磁(ci)(ci)式时间继电器的内(nei)部结构如图4所示,主要由电磁(ci)(ci)机构和钟(zhong)表(biao)延(yan)时机构两部分(fen)组成,电磁(ci)(ci)机构主要起锁住和释(shi)放钟(zhong)表(biao)延(yan)时机构作(zuo)用(yong),钟(zhong)表(biao)延(yan)时机构起准确延(yan)时作(zuo)用(yong)。时间继电器的线圈按短(duan)时工作(zuo)设计。

(4)电(dian)磁式中间(jian)继电(dian)器

中(zhong)间继电器的作用是(shi)为了扩充保(bao)护装置出口继电器的接点数量(liang)和容量(liang),也可以使触(chu)点闭(bi)合或(huo)断开时(shi)带有不(bu)大的延(yan)时(shi)(0.4~0.8s),或(huo)者(zhe)通过继电器的自保(bao)持以适应保(bao)护装置的需(xu)要(yao)。

中间继(ji)(ji)电(dian)器(qi)的工(gong)作原理(li)一般按电(dian)磁(ci)原理(li)构成,如图(tu)5所示为DZ系列电(dian)磁(ci)式中间继(ji)(ji)电(dian)器(qi)结构图(tu)。

(5)电磁式信(xin)号继电器

信(xin)(xin)(xin)(xin)号(hao)继(ji)(ji)电(dian)(dian)器(qi)用于(yu)各保护(hu)装置回路中,作为(wei)保护(hu)动作的(de)指(zhi)示器(qi)。信(xin)(xin)(xin)(xin)号(hao)继(ji)(ji)电(dian)(dian)器(qi)一般(ban)按(an)电(dian)(dian)磁原理构成,继(ji)(ji)电(dian)(dian)器(qi)的(de)电(dian)(dian)磁起动机构采用吸(xi)引衔铁式,由直(zhi)流(liu)电(dian)(dian)源供电(dian)(dian)。DX系列信(xin)(xin)(xin)(xin)号(hao)继(ji)(ji)电(dian)(dian)器(qi)的(de)结构如图6所示。在正常情况下(xia),继(ji)(ji)电(dian)(dian)器(qi)线圈中没有电(dian)(dian)流(liu)通过,信(xin)(xin)(xin)(xin)号(hao)继(ji)(ji)电(dian)(dian)器(qi)在正常位置。当继(ji)(ji)电(dian)(dian)器(qi)线圈中有电(dian)(dian)流(liu)流(liu)过时,信(xin)(xin)(xin)(xin)号(hao)牌(pai)落下(xia)或凸(tu)出,指(zhi)示信(xin)(xin)(xin)(xin)号(hao)继(ji)(ji)电(dian)(dian)器(qi)掉牌(pai)。为(wei)了便于(yu)分析故障的(de)原因,要求信(xin)(xin)(xin)(xin)号(hao)指(zhi)示不能随电(dian)(dian)气量的(de)消失(shi)(shi)而消失(shi)(shi)。因此,信(xin)(xin)(xin)(xin)号(hao)继(ji)(ji)电(dian)(dian)器(qi)须设计(ji)为(wei)手动复归式。

信(xin)(xin)号(hao)(hao)继(ji)电器(qi)可分(fen)为串联(lian)信(xin)(xin)号(hao)(hao)继(ji)电器(qi)(电流信(xin)(xin)号(hao)(hao)继(ji)电器(qi))和并联(lian)信(xin)(xin)号(hao)(hao)继(ji)电器(qi)(电压信(xin)(xin)号(hao)(hao)继(ji)电器(qi)),其(qi)接线(xian)方式(shi)如图7所示(shi)。实际使用(yong)时,一般采用(yong)电流型信(xin)(xin)号(hao)(hao)继(ji)电器(qi)。


© 浙江格亚电气有限公司 版权所有