?變(bian)(bian)(bian)頻(pin)(pin)器(qi)(qi)配套使(shi)用(yong)的(de)(de)電抗(kang)(kang)器(qi)(qi)，通常(chang)是(shi)由變(bian)(bian)(bian)頻(pin)(pin)器(qi)(qi)生(sheng)產(chan)廠家(jia)、或其它生(sheng)產(chan)廠家(jia)生(sheng)產(chan)的(de)(de)變(bian)(bian)(bian)頻(pin)(pin)器(qi)(qi)專用(yong)配套產(chan)品，它是(shi)變(bian)(bian)(bian)頻(pin)(pin)器(qi)(qi)產(chan)品的(de)(de)選購(gou)件。所謂變(bian)(bian)(bian)頻(pin)(pin)器(qi)(qi)選購(gou)件，就(jiu)是(shi)變(bian)(bian)(bian)頻(pin)(pin)器(qi)(qi)正常(chang)銷售出(chu)廠時并不一定向(xiang)用(yong)戶(hu)提(ti)供的(de)(de)配件，即標配以(yi)外的(de)(de)器(qi)(qi)件。而(er)標配包括可以(yi)獨(du)立運行(xing)(xing)的(de)(de)變(bian)(bian)(bian)頻(pin)(pin)器(qi)(qi)整機(ji)、變(bian)(bian)(bian)頻(pin)(pin)器(qi)(qi)說明書、變(bian)(bian)(bian)頻(pin)(pin)器(qi)(qi)合格證、包裝(zhuang)箱以(yi)及一些(xie)(xie)(xie)必要的(de)(de)專用(yong)工具等。這(zhe)些(xie)(xie)(xie)作為選購(gou)件的(de)(de)電抗(kang)(kang)器(qi)(qi)在(zai)變(bian)(bian)(bian)頻(pin)(pin)器(qi)(qi)運行(xing)(xing)現(xian)場應用(yong)很(hen)多，可以(yi)解決一些(xie)(xie)(xie)運行(xing)(xing)現(xian)場的(de)(de)復(fu)雜技術問(wen)題。當然有些(xie)(xie)(xie)運行(xing)(xing)現(xian)場可以(yi)不使(shi)用(yong)電抗(kang)(kang)器(qi)(qi)。

一、三相輸入電抗器

將三相輸入(ru)電(dian)(dian)抗器(qi)L接在電(dian)(dian)源(yuan)和變頻(pin)器(qi)之間，如圖(tu)1所示(shi)，能限制(zhi)電(dian)(dian)網電(dian)(dian)壓突變和操作電(dian)(dian)壓引起的(de)電(dian)(dian)流沖擊，有效地保護變頻(pin)器(qi)并(bing)能夠改善變頻(pin)器(qi)的(de)功率因數，抑制(zhi)變頻(pin)器(qi)輸入(ru)電(dian)(dian)網的(de)諧波電(dian)(dian)流。三相輸入(ru)電(dian)(dian)抗器(qi)的(de)外形如圖(tu)2所示(shi)。

圖(tu)1 變頻器(qi)接入(ru)三相輸入(ru)電(dian)抗器(qi)

圖2 三相(xiang)輸入電(dian)抗器

一般出現如(ru)下情(qing)況時應(ying)使(shi)用三相輸入電(dian)抗器(qi)：

1）一條電(dian)(dian)源供(gong)電(dian)(dian)線(xian)路上(shang)有多臺變頻(pin)(pin)器(qi)同時(shi)(shi)運(yun)行，這時(shi)(shi)變頻(pin)(pin)器(qi)相互之間會(hui)有明顯的干(gan)擾。為了濾除或(huo)減(jian)輕這種干(gan)擾，可使(shi)用三相輸(shu)入電(dian)(dian)抗(kang)器(qi)。

2）電(dian)源相間(jian)電(dian)壓不(bu)平(ping)衡度超過(guo)額定(ding)電(dian)壓的1.8% 。

3）給變頻器(qi)提供電源的變壓器(qi)容(rong)量(liang)較大，數值(zhi)達到變頻器(qi)容(rong)量(liang)的10倍以上時。

4）其(qi)他應(ying)該(gai)使(shi)用輸入電(dian)抗器的情況。

二、三相輸出電抗器

與輸(shu)入電(dian)(dian)(dian)抗(kang)(kang)器一樣(yang)，三(san)相(xiang)輸(shu)出(chu)電(dian)(dian)(dian)抗(kang)(kang)器的(de)(de)(de)結構也是在三(san)相(xiang)鐵心上(shang)繞制三(san)相(xiang)線圈，如圖3所(suo)(suo)示。由于電(dian)(dian)(dian)抗(kang)(kang)器是長期接入電(dian)(dian)(dian)路的(de)(de)(de)，所(suo)(suo)以導線截(jie)面(mian)積應足夠大(da)，允(yun)許長時間流(liu)過變(bian)頻(pin)器的(de)(de)(de)額定電(dian)(dian)(dian)流(liu)。電(dian)(dian)(dian)抗(kang)(kang)器的(de)(de)(de)電(dian)(dian)(dian)感(gan)量以基波電(dian)(dian)(dian)流(liu)流(liu)經電(dian)(dian)(dian)抗(kang)(kang)器時的(de)(de)(de)電(dian)(dian)(dian)壓降(jiang)不(bu)大(da)于額定電(dian)(dian)(dian)壓的(de)(de)(de)3%為(wei)宜。

圖3 三相輸(shu)出(chu)電抗器

如(ru)果電(dian)(dian)(dian)動(dong)機與變(bian)頻(pin)器(qi)(qi)(qi)之間(jian)的距(ju)離無法(fa)減小(xiao)到(dao)規定的數值以內，可以采取在變(bian)頻(pin)器(qi)(qi)(qi)輸(shu)出(chu)(chu)側接入輸(shu)出(chu)(chu)電(dian)(dian)(dian)抗器(qi)(qi)(qi)的方法(fa)，如(ru)圖4所(suo)示(shi)。這時可以適當延(yan)長電(dian)(dian)(dian)動(dong)機與變(bian)頻(pin)器(qi)(qi)(qi)之間(jian)的距(ju)離。輸(shu)出(chu)(chu)電(dian)(dian)(dian)抗器(qi)(qi)(qi)可以補償長線分布電(dian)(dian)(dian)容的影響(xiang)，并(bing)能抑制(zhi)輸(shu)出(chu)(chu)諧波電(dian)(dian)(dian)流(liu)，提高輸(shu)出(chu)(chu)高頻(pin)阻抗,有效抑制(zhi)dv/dt.減低高頻(pin)漏電(dian)(dian)(dian)流(liu),起到(dao)保護變(bian)頻(pin)器(qi)(qi)(qi),減小(xiao)設備噪聲的作用。

圖4 輸出(chu)電抗器的連(lian)接

三、直流電抗器

直流(liu)(liu)(liu)電(dian)(dian)抗(kang)(kang)器又(you)稱平波電(dian)(dian)抗(kang)(kang)器，主(zhu)要(yao)用(yong)于(yu)變流(liu)(liu)(liu)器的(de)直流(liu)(liu)(liu)側，將(jiang)疊加在(zai)直流(liu)(liu)(liu)電(dian)(dian)流(liu)(liu)(liu)上的(de)交流(liu)(liu)(liu)分量限定在(zai)某(mou)一規定值,保持整流(liu)(liu)(liu)電(dian)(dian)流(liu)(liu)(liu)連續性，減(jian)小(xiao)電(dian)(dian)流(liu)(liu)(liu)脈動值,改善輸入功率因(yin)數。一種直流(liu)(liu)(liu)電(dian)(dian)抗(kang)(kang)器的(de)外形如圖(tu)5所示。圖(tu)6所示是接入變頻器電(dian)(dian)路中的(de)直流(liu)(liu)(liu)電(dian)(dian)抗(kang)(kang)器。

圖5 直流電抗器

圖6 直流(liu)電(dian)抗器接入

四、能量回饋電抗器

經常(chang)工作在發電狀(zhuang)態的(de)變(bian)(bian)頻調速系統中，為更好的(de)實現(xian)節能(neng)，把(ba)這部分能(neng)量進行并網或直接通過變(bian)(bian)頻器(qi)直流母線(xian)被其他變(bian)(bian)頻器(qi)負(fu)載吸收(shou)利用(yong)，在此(ci)過程中電抗(kang)(kang)器(qi)主要起到(dao)濾波、降壓、防止涌流沖(chong)擊(ji)以(yi)及(ji)最大限度輸出正弦波電壓和電流的(de)作用(yong)，一般用(yong)在電梯、港口(kou)吊(diao)機(ji)、煤礦井(jing)架(jia)等負(fu)載可能(neng)具(ju)有位能(neng)的(de)場(chang)合，能(neng)量回饋(kui)電抗(kang)(kang)器(qi)采用(yong)優質冷(leng)軋硅剛片和高溫導線(xian)制作，具(ju)有耐動熱穩(wen)定能(neng)力強，電感(gan)穩(wen)定、噪音小等特點。圖7所示為一款回饋(kui)電抗(kang)(kang)器(qi)的(de)外形(xing)圖。

圖7 回饋(kui)電(dian)抗(kang)器(qi)

五、輸入、輸出濾波器
變(bian)頻器(qi)濾波(bo)器(qi)是(shi)一(yi)種(zhong)無源低(di)通濾波(bo)器(qi)，它(ta)是(shi)基于(yu)變(bian)頻器(qi)在(zai)工作時，對電(dian)網及其(qi)他數字電(dian)子設備產生(sheng)干擾(rao)的(de)頻譜分量(liang)電(dian)磁兼容性特點而專門設計的(de)。能有效(xiao)抑制沿電(dian)源線傳播的(de)傳導干擾(rao)。

變頻器(qi)濾(lv)波(bo)(bo)器(qi)有(you)輸(shu)入濾(lv)波(bo)(bo)器(qi)和輸(shu)出濾(lv)波(bo)(bo)器(qi)兩種。一種常用的輸(shu)入濾(lv)波(bo)(bo)器(qi)內部電路(lu)結(jie)構如圖8所(suo)示(shi)。由(you)圖中(zhong)可(ke)見其主要由(you)線圈(quan)、電容器(qi)和電阻等構成。一種輸(shu)入濾(lv)波(bo)(bo)器(qi)的外形見圖9。輸(shu)出濾(lv)波(bo)(bo)器(qi)的外形與此(ci)類似。

圖(tu)8 輸入濾波器內(nei)部電路結構圖(tu)

圖9 輸(shu)入濾波器外形圖

輸(shu)(shu)(shu)出(chu)濾(lv)波(bo)(bo)(bo)(bo)器(qi)(qi)(qi)(qi)與輸(shu)(shu)(shu)入濾(lv)波(bo)(bo)(bo)(bo)器(qi)(qi)(qi)(qi)有一(yi)定的(de)(de)(de)(de)區(qu)別(bie)(bie)，一(yi)是(shi)(shi)線圈(quan)(quan)(quan)的(de)(de)(de)(de)匝(za)數不同(tong)，輸(shu)(shu)(shu)入濾(lv)波(bo)(bo)(bo)(bo)器(qi)(qi)(qi)(qi)線圈(quan)(quan)(quan)的(de)(de)(de)(de)匝(za)數稍(shao)(shao)多(duo)，這(zhe)是(shi)(shi)由于(yu)輸(shu)(shu)(shu)出(chu)電(dian)(dian)(dian)(dian)流(liu)中(zhong)的(de)(de)(de)(de)高(gao)次諧波(bo)(bo)(bo)(bo)分量頻(pin)(pin)率較高(gao)，等(deng)于(yu)載波(bo)(bo)(bo)(bo)頻(pin)(pin)率；輸(shu)(shu)(shu)入端(duan)的(de)(de)(de)(de)諧波(bo)(bo)(bo)(bo)是(shi)(shi)由于(yu)二極管整流(liu)電(dian)(dian)(dian)(dian)路(lu)、電(dian)(dian)(dian)(dian)容充電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)路(lu)形成的(de)(de)(de)(de)，電(dian)(dian)(dian)(dian)源對變頻(pin)(pin)器(qi)(qi)(qi)(qi)的(de)(de)(de)(de)輸(shu)(shu)(shu)入電(dian)(dian)(dian)(dian)流(liu)實際上就是(shi)(shi)電(dian)(dian)(dian)(dian)容器(qi)(qi)(qi)(qi)的(de)(de)(de)(de)充電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流(liu)，這(zhe)里的(de)(de)(de)(de)諧波(bo)(bo)(bo)(bo)頻(pin)(pin)率略低(di)，因此，繞制輸(shu)(shu)(shu)入濾(lv)波(bo)(bo)(bo)(bo)器(qi)(qi)(qi)(qi)線圈(quan)(quan)(quan)的(de)(de)(de)(de)圈(quan)(quan)(quan)數稍(shao)(shao)多(duo)于(yu)輸(shu)(shu)(shu)出(chu)濾(lv)波(bo)(bo)(bo)(bo)器(qi)(qi)(qi)(qi)。兩(liang)者之間(jian)的(de)(de)(de)(de)第二個(ge)區(qu)別(bie)(bie)是(shi)(shi)電(dian)(dian)(dian)(dian)路(lu)結構不同(tong)，各濾(lv)波(bo)(bo)(bo)(bo)器(qi)(qi)(qi)(qi)生產廠(chang)商都會(hui)在(zai)濾(lv)波(bo)(bo)(bo)(bo)線圈(quan)(quan)(quan)兩(liang)端(duan)加接電(dian)(dian)(dian)(dian)容器(qi)(qi)(qi)(qi)，但(dan)在(zai)輸(shu)(shu)(shu)出(chu)濾(lv)波(bo)(bo)(bo)(bo)器(qi)(qi)(qi)(qi)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)路(lu)結構中(zhong)，靠近變頻(pin)(pin)器(qi)(qi)(qi)(qi)的(de)(de)(de)(de)一(yi)側(ce)不允許有電(dian)(dian)(dian)(dian)容器(qi)(qi)(qi)(qi)，在(zai)電(dian)(dian)(dian)(dian)動機一(yi)側(ce)連接的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)容器(qi)(qi)(qi)(qi)應該(gai)串入限流(liu)電(dian)(dian)(dian)(dian)阻。輸(shu)(shu)(shu)出(chu)濾(lv)波(bo)(bo)(bo)(bo)器(qi)(qi)(qi)(qi)的(de)(de)(de)(de)內部電(dian)(dian)(dian)(dian)路(lu)如(ru)圖10所示。

圖(tu)10 輸出濾波器內部電(dian)路結(jie)構圖(tu)

輸入(ru)電(dian)抗(kang)(kang)器(qi)(qi)、輸入(ru)濾波器(qi)(qi)、直流電(dian)抗(kang)(kang)器(qi)(qi)、變(bian)頻器(qi)(qi)、輸出(chu)濾波器(qi)(qi)、輸出(chu)電(dian)抗(kang)(kang)器(qi)(qi)以及(ji)與電(dian)動(dong)機之間的(de)連接(jie)關(guan)系(xi)如(ru)圖11所(suo)示。當(dang)然對于一(yi)個具體的(de)變(bian)頻器(qi)(qi)應用(yong)系(xi)統來(lai)說，最終(zhong)使用哪(na)些非(fei)標配的(de)選購件(jian)應由設計人員根據安(an)裝場所的(de)需求決定。

圖11 電抗器、濾波器與變頻器的連接關系