电(dian)(dian)动(dong)机作为拖动(dong)系统(tong)中(zhong)的(de)(de)(de)(de)(de)(de)重要(yao)(yao)组(zu)成部分在国民经济(ji)中(zhong)占有举足轻重的(de)(de)(de)(de)(de)(de)地(di)位,它(ta)的(de)(de)(de)(de)(de)(de)使用(yong)(yong)几乎渗透到了各(ge)(ge)行(xing)(xing)各(ge)(ge)业(ye)(ye),是(shi)工(gong)业(ye)(ye)、农业(ye)(ye)和(he)国防建设(she)及(ji)人(ren)民生活正常进(jin)行(xing)(xing)的(de)(de)(de)(de)(de)(de)重要(yao)(yao)保(bao)(bao)证,因而(er)(er)确保(bao)(bao)电(dian)(dian)动(dong)机的(de)(de)(de)(de)(de)(de)正常运(yun)行(xing)(xing)就(jiu)显得(de)十(shi)分重要(yao)(yao),而(er)(er)在使用(yong)(yong)中(zhong)造成电(dian)(dian)机烧(shao)毁(hui)甚至引发(fa)重大(da)安全事故(gu)的(de)(de)(de)(de)(de)(de)事件屡见不鲜,据不完全统(tong)计全国每年(nian)仅(jin)因电(dian)(dian)动(dong)机烧(shao)毁(hui)所(suo)消耗的(de)(de)(de)(de)(de)(de)电(dian)(dian)量就(jiu)达数千万度,电(dian)(dian)动(dong)机烧(shao)毁(hui)的(de)(de)(de)(de)(de)(de)数量达20万台(tai)次以(yi)上,容量约0.4亿千瓦(wa),因维修所(suo)耗的(de)(de)(de)(de)(de)(de)电(dian)(dian)磁线(xian)约5000万公斤(jin),修理费达20亿元,而(er)(er)因停工(gong)停产所(suo)造成的(de)(de)(de)(de)(de)(de)损失更(geng)是(shi)一个无(wu)法估(gu)量的(de)(de)(de)(de)(de)(de)巨大(da)数目。因此做(zuo)好电(dian)(dian)动(dong)机的(de)(de)(de)(de)(de)(de)保(bao)(bao)护(hu)具有节能显著(zhu)、提高生产效率和(he)经济(ji)效益及(ji)保(bao)(bao)证安全生产的(de)(de)(de)(de)(de)(de)重要(yao)(yao)意(yi)义。
我国的(de)(de)电(dian)动(dong)机(ji)保(bao)护(hu)装置大约经(jing)历(li)了(le)全面仿苏(su)、自行设计、更(geng)新换(huan)代、智能化(hua)发(fa)展等几个阶段。值得一(yi)提的(de)(de)是由(you)于近年来(lai)微处理器技术的(de)(de)发(fa)展,给(ji)电(dian)动(dong)机(ji)保(bao)护(hu)器向智能化(hua)、多(duo)功能化(hua)方(fang)向发(fa)展提供了(le)硬件平(ping)台,使得电(dian)机(ji)保(bao)护(hu)进入(ru)了(le)一(yi)个飞速(su)发(fa)展的(de)(de)阶段。如下(xia)图
(一)热(re)继电(dian)(dian)器、熔断器和电(dian)(dian)磁式(shi)电(dian)(dian)流继电(dian)(dian)器
在(zai)(zai)建国(guo)(guo)初期(qi),我(wo)们引进了苏联的(de)JR系(xi)列热(re)(re)(re)继(ji)(ji)电(dian)(dian)(dian)器(qi)(qi),从而(er)(er)开始了其(qi)在(zai)(zai)中(zhong)(zhong)国(guo)(guo)电(dian)(dian)(dian)机保护(hu)行业中(zhong)(zhong)长达半个世(shi)纪的(de)生涯,直到1996年(nian)国(guo)(guo)家八部委(wei)联合发文强(qiang)制(zhi)将(jiang)其(qi)淘汰。热(re)(re)(re)继(ji)(ji)电(dian)(dian)(dian)器(qi)(qi)在(zai)(zai)电(dian)(dian)(dian)子业尚不发达的(de)时代曾是电(dian)(dian)(dian)机过(guo)载保护(hu)的(de)首选(xuan)产品(pin),它是利用双金(jin)属片热(re)(re)(re)效应工作的(de),双金(jin)属片是由不同膨胀系(xi)数(shu)的(de)两片金(jin)属铆合而(er)(er)成,当(dang)电(dian)(dian)(dian)流(liu)通过(guo)时它将(jiang)产生热(re)(re)(re)量,并向膨胀系(xi)数(shu)小的(de)一边弯曲,电(dian)(dian)(dian)流(liu)的(de)大小和弯曲的(de)程度成正比,当(dang)电(dian)(dian)(dian)流(liu)超过(guo)热(re)(re)(re)继(ji)(ji)电(dian)(dian)(dian)器(qi)(qi)整(zheng)定(ding)电(dian)(dian)(dian)流(liu)的(de)一定(ding)倍数(shu)时就(jiu)会启动其(qi)中(zhong)(zhong)的(de)脱扣装(zhuang)置从而(er)(er)切(qie)断主回(hui)路达到保护(hu)的(de)目(mu)的(de)。但热(re)(re)(re)继(ji)(ji)电(dian)(dian)(dian)器(qi)(qi)存在(zai)(zai)致(zhi)命的(de)缺(que)陷,包(bao)括整(zheng)定(ding)粗糙、受环境影响(xiang)大、重复性差、误差大及功能单一等,已无法满足越(yue)(yue)来(lai)越(yue)(yue)高(gao)的(de)要(yao)求,因而(er)(er)也(ye)就(jiu)无法避免被淘汰的(de)命运。
很多(duo)人(ren)把熔断器作为(wei)电(dian)机的(de)(de)过(guo)载(zai)保(bao)护,其(qi)(qi)实这是一(yi)种不(bu)科学的(de)(de)做法。因为(wei)首先受其(qi)(qi)规格(ge)限(xian)制无法按电(dian)机额(e)定电(dian)流(liu)进行准确设定,况(kuang)且如果(guo)熔断器规格(ge)选得太小容易造成断路,使电(dian)机单相运行,如果(guo)熔断器规格(ge)选得太大,则达不(bu)到(dao)过(guo)载(zai)保(bao)护的(de)(de)效果(guo)。
电磁(ci)式电流继电器具有过载(zai)、堵转保(bao)护功能(neng),有的还有缺相保(bao)护,其(qi)过载(zai)保(bao)护具有反时(shi)限特性(xing),但其(qi)结(jie)构复(fu)杂,机械(xie)制造(zao)精(jing)度高,价(jia)格高且(qie)体(ti)积庞大,因而目前已被基本淘(tao)汰。
(二)模拟(ni)电(dian)子(zi)式(shi)电(dian)动(dong)机(ji)保护(hu)器(电(dian)机(ji)保护(hu)器)
在上个世纪(ji)七八十年代(dai),随着(zhe)半导体模拟器件的(de)(de)兴起(qi)及(ji)普及(ji),涌现出了(le)一(yi)批性能(neng)比(bi)较(jiao)可靠(kao)、功能(neng)多(duo)样(yang)化的(de)(de)电(dian)子式电(dian)动机(ji)(ji)保(bao)护器(电(dian)机(ji)(ji)保(bao)护器),为电(dian)机(ji)(ji)的(de)(de)可靠(kao)运行提供了(le)较(jiao)可靠(kao)的(de)(de)保(bao)障,其(qi)中得到公众(zhong)认(ren)可且具有(you)自己品(pin)牌特色的(de)(de)以韩国三(san)和技研株式会社(she)的(de)(de)产品(pin)为代(dai)表(biao),在国内(nei)市场具有(you)一(yi)定影响(xiang),他(ta)们的(de)(de)产品(pin)品(pin)种(zhong)多(duo)样(yang),规格齐全,主要功能(neng)包括:缺(que)(que)相,过载,欠流,相失衡,相序,接(jie)地,短路,过欠压(ya),电(dian)流显示,声光报警及(ji)变(bian)送输出等,但这类产品(pin)仍(reng)存在一(yi)些无法克服的(de)(de)缺(que)(que)陷(xian),包括如(ru)下(xia)几(ji)个方面:
1.整定(ding)精度(du)不(bu)高,模拟电(dian)(dian)(dian)子式(shi)电(dian)(dian)(dian)动机(ji)保(bao)护器(电(dian)(dian)(dian)机(ji)保(bao)护器)均(jun)采用电(dian)(dian)(dian)位器进行额(e)定(ding)电(dian)(dian)(dian)流的(de)整定(ding),然而(er)要使电(dian)(dian)(dian)位器滑(hua)动臂(bei)的(de)旋转角度(du)与其(qi)阻值(zhi)成较(jiao)好的(de)线形(xing)关系(xi)比较(jiao)困(kun)难(nan),特(te)(te)别是(shi)在(zai)大批(pi)量生产(chan)中更是(shi)难(nan)以(yi)做(zuo)到(dao),另外,操作(zuo)者的(de)整定(ding)误差也是(shi)难(nan)以(yi)避免的(de),特(te)(te)别是(shi)对于那些没(mei)有设定(ding)值(zhi)显示的(de)产(chan)品。
2.采样(yang)精度不高(gao),模(mo)拟线(xian)(xian)路对电(dian)(dian)(dian)流互感(gan)器的非(fei)线(xian)(xian)性问题(ti)束手无策,即使(shi)可以校(xiao)正(zheng)也(ye)会使(shi)线(xian)(xian)路变得非(fei)常复杂,甚至无法实际使(shi)用(yong),因而大部(bu)分厂家(jia)只好(hao)将非(fei)线(xian)(xian)性问题(ti)依赖于(yu)提高(gao)电(dian)(dian)(dian)流互感(gan)器的线(xian)(xian)性,而实际上(shang)要想(xiang)由矽钢片做成的电(dian)(dian)(dian)流互感(gan)器在(zai)很宽(kuan)的范(fan)围内保(bao)(bao)持线(xian)(xian)性是非(fei)常困难的,行(xing)内人(ren)士知道用(yong)于(yu)电(dian)(dian)(dian)动机保(bao)(bao)护(hu)器(电(dian)(dian)(dian)机保(bao)(bao)护(hu)器)采样(yang)的电(dian)(dian)(dian)流互感(gan)器需考虑的最大使(shi)用(yong)范(fan)围至少为被保(bao)(bao)护(hu)电(dian)(dian)(dian)机额(e)定(ding)电(dian)(dian)(dian)流的7倍(bei),因为电(dian)(dian)(dian)动机在(zai)堵转情况下会达(da)到5-7倍(bei)的额(e)定(ding)电(dian)(dian)(dian)流;另外,采样(yang)线(xian)(xian)路本身也(ye)存(cun)在(zai)非(fei)线(xian)(xian)性问题(ti)。基于(yu)这(zhei)些(xie)技术难题(ti),要实现高(gao)精度的采样(yang)自然就成了(le)一句空话。
3.无(wu)法实(shi)现具(ju)有多种保(bao)护(hu)功能于(yu)一体的全(quan)保(bao)护(hu),随着社会的发(fa)展,人(ren)们对电机(ji)保(bao)护(hu)的要(yao)求也(ye)越(yue)来越(yue)高,希望电动机(ji)保(bao)护(hu)器(qi)(电机(ji)保(bao)护(hu)器(qi))的功能多样化,性能可(ke)靠,接线(xian)简单,界面直观且体积要(yao)小(xiao),这些都是纯粹(cui)的模拟线(xian)路根本(ben)无(wu)法实(shi)现的。
鉴于以上(shang)原因,纯(chun)粹模(mo)拟线路的电(dian)动机(ji)保护器(电(dian)机(ji)保护器)正逐渐(jian)被其(qi)它一些更(geng)先进(jin)的技术产品所代替(ti)。
(三)数字电子式电动机(ji)保(bao)护(hu)器(qi)(电机(ji)保(bao)护(hu)器(qi))
这(zhei)类电动(dong)机(ji)(ji)保(bao)护(hu)器(qi)(电机(ji)(ji)保(bao)护(hu)器(qi))主(zhu)要以(yi)单片机(ji)(ji)作(zuo)为控(kong)制器(qi),可(ke)实现电机(ji)(ji)的(de)(de)(de)(de)(de)(de)智(zhi)能(neng)(neng)化(hua)综(zong)合(he)保(bao)护(hu),有(you)的(de)(de)(de)(de)(de)(de)还具有(you)远程通讯(xun)功(gong)能(neng)(neng),可(ke)在PC机(ji)(ji)上实现对(dui)多(duo)达256台联网的(de)(de)(de)(de)(de)(de)电机(ji)(ji)实现在线(xian)(xian)(xian)综(zong)合(he)监视与控(kong)制,在采(cai)(cai)(cai)样(yang)和整定精度(du)(du)方(fang)(fang)面有(you)质的(de)(de)(de)(de)(de)(de)飞跃,可(ke)对(dui)采(cai)(cai)(cai)样(yang)信号进行软件(jian)非线(xian)(xian)(xian)性(xing)校正,并可(ke)实现真有(you)效(xiao)值,从而极大(da)地降低(di)了被测(ce)(ce)信号波形畸变的(de)(de)(de)(de)(de)(de)影响,真正实现了高精度(du)(du)采(cai)(cai)(cai)样(yang),在整定方(fang)(fang)面采(cai)(cai)(cai)用(yong)(yong)(yong)数(shu)字设(she)定,通过键盘由用(yong)(yong)(yong)户(hu)自行现场设(she)定,不存在误差,还可(ke)为过载保(bao)护(hu)设(she)置多(duo)条更科学的(de)(de)(de)(de)(de)(de)反时(shi)限曲线(xian)(xian)(xian)。因(yin)为采(cai)(cai)(cai)用(yong)(yong)(yong)了单片机(ji)(ji)就使(shi)得(de)在相同(tong)(tong)硬(ying)件(jian)条件(jian)下集多(duo)种功(gong)能(neng)(neng)与一体的(de)(de)(de)(de)(de)(de)综(zong)合(he)保(bao)护(hu)器(qi)的(de)(de)(de)(de)(de)(de)出(chu)现成为可(ke)能(neng)(neng),我公司研发(fa)生产(chan)的(de)(de)(de)(de)(de)(de)RKP260系列智(zhi)能(neng)(neng)低(di)压(ya)电动(dong)机(ji)(ji)保(bao)护(hu)器(qi)具有(you)远程通讯(xun)、过载、堵转、短(duan)路(lu)、漏电、欠(qian)流、故障记忆(yi)等多(duo)种功(gong)能(neng)(neng),它采(cai)(cai)(cai)用(yong)(yong)(yong)交流采(cai)(cai)(cai)样(yang)技(ji)术、多(duo)点线(xian)(xian)(xian)性(xing)校正技(ji)术、量(liang)程自动(dong)切换技(ji)术,使(shi)其在0.4A-800A的(de)(de)(de)(de)(de)(de)测(ce)(ce)量(liang)范围内都能(neng)(neng)保(bao)持很高的(de)(de)(de)(de)(de)(de)采(cai)(cai)(cai)样(yang)精度(du)(du),在国(guo)内外同(tong)(tong)类产(chan)品中处于领先(xian)地位。随着(zhe)微电子(zi)技(ji)术的(de)(de)(de)(de)(de)(de)发(fa)展(zhan),电动(dong)机(ji)(ji)保(bao)护(hu)器(qi)(电机(ji)(ji)保(bao)护(hu)器(qi))正朝着(zhe)智(zhi)能(neng)(neng)化(hua),综(zong)合(he)化(hua),高精度(du)(du),高可(ke)靠方(fang)(fang)向(xiang)发(fa)展(zhan)。
(四)结束语
同所(suo)有的(de)产品一样,电(dian)(dian)动机保(bao)(bao)(bao)护(hu)(hu)(hu)器(电(dian)(dian)机保(bao)(bao)(bao)护(hu)(hu)(hu)器)经历了由低级到(dao)(dao)高级、由简单到(dao)(dao)复(fu)杂逐渐(jian)科(ke)学完善的(de)发(fa)展(zhan)过程,在这个过程中一批批技术人(ren)员(yuan)倾注了大量的(de)热情与心血。虽然(ran)电(dian)(dian)动机保(bao)(bao)(bao)护(hu)(hu)(hu)器(电(dian)(dian)机保(bao)(bao)(bao)护(hu)(hu)(hu)器)已(yi)发(fa)展(zhan)到(dao)(dao)了微电(dian)(dian)子(zi)时代,但我(wo)想,电(dian)(dian)动机保(bao)(bao)(bao)护(hu)(hu)(hu)器(电(dian)(dian)机保(bao)(bao)(bao)护(hu)(hu)(hu)器)的(de)课题将永远不会停止,仍然(ran)需要我(wo)们(men)百倍努(nu)力,仍有大量的(de)工(gong)作等着(zhe)我(wo)们(men)去做,例如:电(dian)(dian)动机保(bao)(bao)(bao)护(hu)(hu)(hu)器(电(dian)(dian)机保(bao)(bao)(bao)护(hu)(hu)(hu)器)仍没有国(guo)家标准,导致市场上产品良莠(you)不齐,这就说明电(dian)(dian)动机保(bao)(bao)(bao)护(hu)(hu)(hu)器(电(dian)(dian)机保(bao)(bao)(bao)护(hu)(hu)(hu)器)成长之(zhi)路还很漫长,我(wo)们(men)期(qi)待着(zhe)电(dian)(dian)机保(bao)(bao)(bao)护(hu)(hu)(hu)行业的(de)健康发(fa)展(zhan)。
参考文献:
1、低(di)压电动机(ji)保护器行业标准 JB/T 10736-2007
2、佟为明,赵(zhao)志衡, 一(yi)种微机(ji)式电(dian)动机(ji)综合(he)保(bao)护器(qi)的研(yan)制(zhi)
3、许志(zhi)红(hong),张(zhang)培铭, 智(zhi)能电动机控制与(yu)保护器的研究
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