20AD5P0A3AYNANC0 20AD5P0A3AYNANC0
優(yōu)勢品牌：Allen-Bradley Siemens ABB
庫存現(xiàn)貨 *優(yōu)惠
陜西欣鴻然自動化設(shè)備有限公司
:寧超
：
:1293858601
:1293858601
傳真:
地址：西安市灞橋區(qū)浐河東路水岸東方1單元14棟602室。
基本組成
變頻器通常分為4部分：整流單元、高容量電容、逆變器和控制器。
整流單元：將工作頻率固定的交流電轉(zhuǎn)換為直流電。
高容量電容：存儲轉(zhuǎn)換后的電能。
逆變器：由大功率開關(guān)晶體管陣列組成電子開關(guān)，將直流電轉(zhuǎn)化成不同頻率、寬度、幅度的方波。
控制器：按設(shè)定的程序工作，控制輸出方波的幅度與脈寬，使疊加為近似正弦波的交流電，驅(qū)動交流電動機。
（1）運算電路：將外部的速度、轉(zhuǎn)矩等指令同檢測電路的電流、電壓信號進行比較運算，決定逆變器的輸出電壓、頻率。
（2）電壓、電流檢測電路：與主回路電位隔離檢測電壓、電流等。
（3）驅(qū)動電路：驅(qū)動主電路器件的電路。它與控制電路隔離使主電路器件導通、關(guān)斷。
（4）速度檢測電路:以裝在異步電動機軸機上的速度檢測器(tg、plg等)的信號為速度信號，送入運算回路，根據(jù)指令和運算可使電動機按指令速度運轉(zhuǎn)。
（5）保護電路：檢測主電路的電壓、電流等，當發(fā)生過載或過電壓等異常時，為了防止逆變器和異步電動機損壞
直流電動拖動和交流電動機拖動先后生于19世紀，距今已有100多年的歷史，并已成為動力機械的主要驅(qū)動裝置。由于當時的技術(shù)問題，在很長的一個時間內(nèi)，需要進行調(diào)速控制的拖動系統(tǒng)中則基本上采用的是直流電動機。
直流電動機存在以下缺點是由于結(jié)構(gòu)上的原因：
1、由于直流電動機存在換向火花，難以應用于存在易燃易爆氣體的惡劣環(huán)境;
2、需要定期更換電刷和換向器，維護保養(yǎng)困難，壽命較短;
3、結(jié)構(gòu)復雜，難以制造大容量、高轉(zhuǎn)速和高電壓的直流電動機。
（1）信號線與動力線要垂直交叉或分槽布線。
（2）不要采用不同金屬的導線相互連接。
（3）屏蔽管（層）應可靠接地，并保證整個長度上連續(xù)可靠接地。
（4）信號電路中要使用雙絞線屏蔽電纜。
（5）屏蔽層接地點盡量遠離變頻器，并與變頻器接地點分開。
（6）磁環(huán)可以在變頻器輸入電源線和輸出線上使用，具體方法為：輸入線一起朝同一方向繞4圈，而輸出線朝同一方向繞3圈即可。繞線時需注意，盡量將磁環(huán)靠近變頻器。
（7）一般對被干擾設(shè)備儀器，均可采取屏蔽及其它抗干擾措施。
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The gentleman is not close to the evil.Emperor lost ground, name;Out the surname, name.
A minister of the: don't fight.Three to fight and don't listen to, it escaped.
Son also things: three suggestion and don't listen to, the tears and then.You have a disease, drink medicine, I taste the first.Have a disease, drink medicine, first taste of the children.
D not iii, take the medicine.
儗 shall in its Aaron.
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Number of rich, ask the monarch to, out of the world.Ask the doctor of the rich, have to kill the feed force, phenomena of clothes is not false.Ask the rich, to car number.Ask the common people of the rich, number of livestock.
Son of heaven to worship, sacrifice, the mountains and rivers, the five si, old times.Governors si, offering mountains and rivers, offering five si, old times.The doctor offering five si, old times.And offering its first.
