輸出電抗器

發布日期：2018-11-15 15:39 來源：//ultrarunning.cn 點擊：

1.1、鐵芯式輸出電抗(kang)器

當(dang)變(bian)頻(pin)器的載波(bo)頻(pin)率小于3KHZ時采用鐵芯式(shi)輸出電(dian)抗(kang)器。

1.2、鐵氧體式輸出電抗器

當變頻器的載(zai)波頻率小于(yu)6KHZ時采用鐵氧體(ti)式(shi)輸(shu)出電抗器。

為了補償變(bian)(bian)(bian)頻(pin)器(qi)與(yu)電(dian)(dian)(dian)(dian)動機(ji)(ji)之間(jian)連接(jie)電(dian)(dian)(dian)(dian)纜線(xian)分布電(dian)(dian)(dian)(dian)容的(de)影響，有效抑制變(bian)(bian)(bian)頻(pin)器(qi)輸出(chu)的(de)諧波，減(jian)(jian)小(xiao)(xiao)變(bian)(bian)(bian)頻(pin)器(qi)的(de)噪聲，以(yi)避免(mian)電(dian)(dian)(dian)(dian)動機(ji)(ji)絕緣(yuan)過早老(lao)化或導致電(dian)(dian)(dian)(dian)動機(ji)(ji)的(de)早期(qi)損壞(huai)。安(an)裝(zhuang)在變(bian)(bian)(bian)頻(pin)器(qi)輸入與(yu)輸出(chu)保護電(dian)(dian)(dian)(dian)路中的(de)輸出(chu)電(dian)(dian)(dian)(dian)抗器(qi)，就是用(yong)來(lai)減(jian)(jian)少在電(dian)(dian)(dian)(dian)動機(ji)(ji)端子的(de)du/dt值。當(dang)變(bian)(bian)(bian)頻(pin)器(qi)與(yu)電(dian)(dian)(dian)(dian)動機(ji)(ji)之間(jian)采用(yong)長電(dian)(dian)(dian)(dian)纜進行連接(jie)時，輸出(chu)電(dian)(dian)(dian)(dian)抗器(qi)就可以(yi)減(jian)(jian)小(xiao)(xiao)負荷電(dian)(dian)(dian)(dian)流的(de)峰值。不(bu)過，設置在變(bian)(bian)(bian)頻(pin)器(qi)輸出(chu)端的(de)輸出(chu)電(dian)(dian)(dian)(dian)抗器(qi)不(bu)能用(yong)來(lai)減(jian)(jian)小(xiao)(xiao)電(dian)(dian)(dian)(dian)動機(ji)(ji)上瞬變(bian)(bian)(bian)電(dian)(dian)(dian)(dian)壓的(de)峰值。 [1]

輸(shu)出電抗(kang)器主要在(zai)以下兩個方面(mian)發揮作用(yong)：

1、增大變頻器的有效傳輸距離

當變(bian)(bian)頻(pin)器輸(shu)(shu)出到電機的(de)電纜(lan)長度(du)大于(yu)產品規定值(zhi)時(shi)，應加輸(shu)(shu)出電抗(kang)器來補償電機長電纜(lan)運行時(shi)的(de)耦合電容的(de)充(chong)放電影(ying)響(xiang)，避免(mian)變(bian)(bian)頻(pin)器過流，增(zeng)大了變(bian)(bian)頻(pin)器到電動機的(de)有(you)效傳輸(shu)(shu)距離。

2、有(you)效抑制IGBT開關時的瞬間高(gao)壓

變頻(pin)器輸(shu)(shu)出端(duan)增加(jia)輸(shu)(shu)出電(dian)抗(kang)器的作用是為了輸(shu)(shu)出電(dian)抗(kang)器可以有效抑制變頻(pin)器的IGBT開關時(shi)產生的瞬(shun)間高電(dian)壓，減(jian)少此電(dian)壓對(dui)電(dian)纜絕緣和電(dian)機的不良影響(xiang)。

使用說明編輯

為了(le)增加變頻(pin)器到電機之間的距離可以適當加粗電纜(lan)，增加電纜(lan)的絕緣強度，盡量選用屏蔽電纜(lan)。

由于變(bian)(bian)頻器的(de)(de)輸出電壓(ya)中(zhong)高次諧(xie)波(bo)較(jiao)多，故(gu)變(bian)(bian)頻器和電動(dong)機(ji)之(zhi)間的(de)(de)傳輸線(xian)不(bu)可過(guo)長。如果導線(xian)過(guo)長，它的(de)(de)分(fen)布電容也就大。這樣，在諧(xie)波(bo)電壓(ya)的(de)(de)作用(yong)下，高次諧(xie)波(bo)電流也將過(guo)大。

因(yin)此，當(dang)變頻器與電動機之間的輸(shu)出(chu)電纜過長(chang)時，就應設置輸(shu)出(chu)電抗(kang)器。

變頻器(qi)輸(shu)入與(yu)輸(shu)出保護電路中輸(shu)出電抗器(qi)的(de)參數選擇，其計算與(yu)設(she)計的(de)原則與(yu)輸(shu)入電抗器(qi)基(ji)本相同，但輸(shu)出電抗器(qi)的(de)電感量是以基(ji)波電流(liu)流(liu)經(jing)電抗器(qi)時的(de)電壓不大(da)于額定電壓為佳(jia)。 [1]