在(zai)变压(ya)器(qi)(qi)行(xing)业(ye)常用(yong)的(de)连接(jie)组别一般有(you)Dyn11跟Yyn0，可能大家(jia)都知道这2种，但是要(yao)怎么来区别认识(shi)了，Dyn11联结的(de)好处是有(you)利于抑(yi)制高(gao)次(ci)谐(xie)(xie)(xie)波(bo)(bo)(bo)(bo)(bo)电(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)。对Yyn0结线(xian)(xian)的(de)三相(xiang)变压(ya)器(qi)(qi)，原(yuan)边星(xing)形(xing)(xing)(xing)连接(jie)而无中线(xian)(xian)，故三次(ci)谐(xie)(xie)(xie)波(bo)(bo)(bo)(bo)(bo)电(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)不(bu)能流(liu)(liu)(liu)通(tong)。原(yuan)边激磁(ci)电(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)波(bo)(bo)(bo)(bo)(bo)形(xing)(xing)(xing)为(wei)(wei)(wei)正弦波(bo)(bo)(bo)(bo)(bo)时，则铁芯中磁(ci)通(tong)为(wei)(wei)(wei)平(ping)顶波(bo)(bo)(bo)(bo)(bo)，副边感应(ying)电(dian)(dian)(dian)(dian)(dian)(dian)势(shi)波(bo)(bo)(bo)(bo)(bo)形(xing)(xing)(xing)所(suo)含高(gao)次(ci)谐(xie)(xie)(xie)波(bo)(bo)(bo)(bo)(bo)分量大；激磁(ci)电(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)中以三次(ci)谐(xie)(xie)(xie)波(bo)(bo)(bo)(bo)(bo)为(wei)(wei)(wei)主的(de)高(gao)次(ci)谐(xie)(xie)(xie)波(bo)(bo)(bo)(bo)(bo)电(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)在(zai)原(yuan)边接(jie)成(cheng)三角形(xing)(xing)(xing)条件下，可在(zai)原(yuan)边形(xing)(xing)(xing)成(cheng)环流(liu)(liu)(liu)，与原(yuan)边接(jie)成(cheng)星(xing)形(xing)(xing)(xing)相(xiang)比(bi)，有(you)利于抑(yi)制高(gao)次(ci)谐(xie)(xie)(xie)波(bo)(bo)(bo)(bo)(bo)电(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)。在(zai)当前电(dian)(dian)(dian)(dian)(dian)(dian)网中接(jie)用(yong)电(dian)(dian)(dian)(dian)(dian)(dian)力电(dian)(dian)(dian)(dian)(dian)(dian)子元件、气体放电(dian)(dian)(dian)(dian)(dian)(dian)灯(deng)等日益广泛、其功率越来越大的(de)情况下，会使得电(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)波(bo)(bo)(bo)(bo)(bo)形(xing)(xing)(xing)畸变。即(ji)使三相(xiang)负荷平(ping)衡，中性线(xian)(xian)中也流(liu)(liu)(liu)过(guo)以3次(ci)谐(xie)(xie)(xie)波(bo)(bo)(bo)(bo)(bo)为(wei)(wei)(wei)主的(de)高(gao)次(ci)谐(xie)(xie)(xie)波(bo)(bo)(bo)(bo)(bo)电(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)。配电(dian)(dian)(dian)(dian)(dian)(dian)变压(ya)器(qi)(qi)的(de)原(yuan)边（常为(wei)(wei)(wei)10KV侧）采用(yong)三角形(xing)(xing)(xing)结线(xian)(xian)就抑(yi)制了此类高(gao)次(ci)谐(xie)(xie)(xie)波(bo)(bo)(bo)(bo)(bo)电(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)，这样(yang)就能保证供电(dian)(dian)(dian)(dian)(dian)(dian)波(bo)(bo)(bo)(bo)(bo)形(xing)(xing)(xing)的(de)质(zhi)量。

    第二，有利于单(dan)相(xiang)接(jie)地短路(lu)故(gu)障的(de)(de)切除：原(yuan)边(bian)（高(gao)压(ya)(ya)(ya)）接(jie)成三角形（D接(jie)），绕组内可通(tong)过零序(xu)循环电(dian)(dian)(dian)流(liu)(liu)（感应产生），因而可与低压(ya)(ya)(ya)绕组零序(xu)电(dian)(dian)(dian)流(liu)(liu)互相(xiang)平衡、去磁(ci)，因此(ci)，副边(bian)（低压(ya)(ya)(ya)侧）零序(xu)阻(zu)抗很小；若原(yuan)边(bian)（高(gao)压(ya)(ya)(ya)侧）星接(jie)（Y接(jie)），绕组不能(neng)流(liu)(liu)过零序(xu)电(dian)(dian)(dian)流(liu)(liu)，低压(ya)(ya)(ya)侧激磁(ci)时(shi)，其(qi)零序(xu)电(dian)(dian)(dian)流(liu)(liu)在(zai)变(bian)压(ya)(ya)(ya)器铁芯(xin)(xin)中产生零序(xu)磁(ci)通(tong)，但其(qi)磁(ci)路(lu)不能(neng)在(zai)铁芯(xin)(xin)内形成闭合，要(yao)走铁芯(xin)(xin)外面(mian)的(de)(de)空气，其(qi)磁(ci)阻(zu)很大，变(bian)压(ya)(ya)(ya)器的(de)(de)零序(xu)阻(zu)抗较(jiao)大。若发生单(dan)相(xiang)短路(lu)，其(qi)短路(lu)电(dian)(dian)(dian)流(liu)(liu)值就会相(xiang)对(dui)地减小，致使在(zai)很多(duo)情况(kuang)下(xia)，其(qi)单(dan)相(xiang)接(jie)地短路(lu)电(dian)(dian)(dian)流(liu)(liu)几(ji)乎不能(neng)使低压(ya)(ya)(ya)断(duan)路(lu)器快(kuai)速动(dong)作或使熔(rong)断(duan)器迅速熔(rong)断(duan)。通(tong)常，在(zai)相(xiang)同的(de)(de)条件下(xia)，Dyn11结线的(de)(de)变(bian)压(ya)(ya)(ya)器配(pei)电(dian)(dian)(dian)系统的(de)(de)单(dan)相(xiang)短路(lu)电(dian)(dian)(dian)流(liu)(liu)为Yyn0结线时(shi)的(de)(de)3倍以上。因此(ci)，Dyn11结线有利于单(dan)相(xiang)接(jie)地短路(lu)故(gu)障的(de)(de)切除。

    第三，能(neng)(neng)(neng)充分利用变(bian)(bian)(bian)压(ya)(ya)(ya)(ya)器的(de)(de)设备能(neng)(neng)(neng)力：对于配电(dian)(dian)(dian)(dian)(dian)变(bian)(bian)(bian)压(ya)(ya)(ya)(ya)器，照明、空调、电(dian)(dian)(dian)(dian)(dian)炊、电(dian)(dian)(dian)(dian)(dian)热等(deng)餐(can)厨家电(dian)(dian)(dian)(dian)(dian)220伏单(dan)相(xiang)负(fu)荷(he)(he)往(wang)往(wang)占很大比(bi)重。尽管在(zai)工程设计(ji)及安装(zhuang)时(shi)(shi)，尽可能(neng)(neng)(neng)将各个单(dan)相(xiang)负(fu)荷(he)(he)均(jun)匀分布在(zai)三相(xiang)上(shang)，而由于运行时(shi)(shi)的(de)(de)情况千(qian)变(bian)(bian)(bian)万化，有时(shi)(shi)可能(neng)(neng)(neng)出现三相(xiang)严重不(bu)平衡(heng)(heng)现象(xiang)。三相(xiang)负(fu)荷(he)(he)不(bu)平衡(heng)(heng)或每(mei)相(xiang)功率因(yin)数相(xiang)差较大、变(bian)(bian)(bian)压(ya)(ya)(ya)(ya)器处于不(bu)对称运行状态(tai)，副边中性线(xian)就(jiu)有电(dian)(dian)(dian)(dian)(dian)流(liu)(liu)通过。上(shang)述《规(gui)范》中第6.0.8条明确规(gui)定(ding)：“在(zai)TN和TT系统接(jie)地型式的(de)(de)低(di)压(ya)(ya)(ya)(ya)电(dian)(dian)(dian)(dian)(dian)网中，当选用Yyn0结线(xian)组别的(de)(de)三相(xiang)变(bian)(bian)(bian)压(ya)(ya)(ya)(ya)器时(shi)(shi)，其(qi)由单(dan)相(xiang)不(bu)平衡(heng)(heng)负(fu)荷(he)(he)引起的(de)(de)中性线(xian)电(dian)(dian)(dian)(dian)(dian)流(liu)(liu)不(bu)得超(chao)过低(di)压(ya)(ya)(ya)(ya)绕组额(e)定(ding)电(dian)(dian)(dian)(dian)(dian)流(liu)(liu)的(de)(de)25％，且其(qi)一相(xiang)的(de)(de)电(dian)(dian)(dian)(dian)(dian)流(liu)(liu)在(zai)满载时(shi)(shi)不(bu)得超(chao)过额(e)定(ding)电(dian)(dian)(dian)(dian)(dian)流(liu)(liu)值。”

    这(zhei)一规定十分明确地限制了Yyn0结(jie)线(xian)时接用(yong)单(dan)相负(fu)荷的(de)(de)容(rong)量(liang)，从而(er)限制了Yyn0结(jie)线(xian)配电(dian)变压(ya)器的(de)(de)使(shi)用(yong)――此时，变压(ya)器设备能力不能充分利(li)用(yong)。而(er)Dyn11结(jie)线(xian)方式的(de)(de)变压(ya)器，对(dui)中(zhong)性(xing)线(xian)电(dian)流没有限制，可达变压(ya)器低压(ya)侧之线(xian)（相）电(dian)流，从而(er)能充分利(li)用(yong)变压(ya)器的(de)(de)容(rong)量(liang)、发挥(hui)其设备能力，尤(you)其适宜以单(dan)相负(fu)荷为主而(er)出现三相不平(ping)衡的(de)(de)配电(dian)变压(ya)器。