6ES72121BB230XB0

變頻器的調(diào)速原理主要受制于異步電動機(jī)的轉(zhuǎn)速n、異步電動機(jī)的頻率f、電動機(jī)轉(zhuǎn)差率s、電動機(jī)極對數(shù)p這四個因素。轉(zhuǎn)速n與頻率f成正比，只要改變頻率f即可改變電動機(jī)的轉(zhuǎn)速，當(dāng)頻率f在0-50Hz的范圍內(nèi)變化時，電動機(jī)轉(zhuǎn)速調(diào)節(jié)范圍非常寬。變頻調(diào)速就是通過改變電動機(jī)電源頻率實現(xiàn)速度調(diào)節(jié)的。

主要采用交—直—交方式，先把工頻交流電源通過整流器轉(zhuǎn)換成直流電源，然后再把直流電源轉(zhuǎn)換成頻率、電壓均可控制的交流電源以供給電動機(jī)。變頻器的電路一般由整流、中間直流環(huán)節(jié)、逆變和控制4個部分組成。整流部分為三相橋式不可控整流器，逆變部分為IGBT三相橋式逆變器，且輸出為PWM波形，中間直流環(huán)節(jié)為濾波、直流儲能和緩沖無功功率。

伺服系統(tǒng)的工作原理簡單的說就是在開環(huán)控制的交直流電機(jī)的基礎(chǔ)上將速度和位置信號通過旋轉(zhuǎn)編碼器、旋轉(zhuǎn)變壓器等反饋給驅(qū)動器做閉環(huán)負(fù)反饋的PID調(diào)節(jié)控制。再加上驅(qū)動器內(nèi)部的電流閉環(huán)，通過這3個閉環(huán)調(diào)節(jié)，使電機(jī)的輸出對設(shè)定值追隨的準(zhǔn)確性和時間響應(yīng)特性都提高很多。伺服系統(tǒng)是個動態(tài)的隨動系統(tǒng)，達(dá)到的穩(wěn)態(tài)平衡也是動態(tài)的平衡。

6ES72121BB230XB0
Cutler Hammer LTDD2048S Panel Board Cover

Cutler Hammer LT20485 Panel Cover * IN BOX*

Allen Bradley Size 5 Starter, 509-FOD **

Allen Bradley Size 6 Starter, 509-G0B **

General Electric Size 5 Contactor, CR305GO**CAKH

General Electric Size 6 Contactor, CR305HHD**BA1H

Cutler Hammer HPG49755-A01, 800 Amp Tap Box 

Siemens 4300 Power Meter **

15 KVA, 1 Phase, 240x480 X 120/240 Volt Transber

GS Hevi Duty 63 KVA SCR Drive Trans,460X460Y/266, 3 Ph

Siemens 30 KVA Transber, 480 x 120/208 Volt

Square D 45 KVA, 480/277 x 208 Volt Transber

Federal Pacific 37.5 KVA,480X120/208 3 Ph, Trans

Square D HU368, 1200 Amp Disconnect * SURPLUS*

GE 25 KVA Transber, 1 Phase 600X120/240 volt

Westinghouse 25 KVA Transber, 600 x 120/240 Volt

ACME 25 KVA,600X120/240, 1 Phase Trans

GS Hevi Duty 7.5 KVA, 575X575/332, 3 Ph Trans

REX 25 KVA, 1 Ph, 600X120/240 Volt Trans 

Marelco 55 KVA Transber, 3 Phase, 208x240 X 400 Volt

Federal Pacific 10 KVA 240X480X120/240, NEMA 3R, 1 Ph

Jefferson 25 KVA, 480X120/240, 1 Ph Trans **

Square D 225 Amp Main Lug I-Line Panelboard **

Federal Pacific 15 KVA, 3 Ph 480X460Y/277 Transber 

GS Hevi Duty Electric 25 KVA 575X120/240 1PHTransber

GE 150 KVA 600X277/480 Transber, 3 Phase 

Hitran 27 KVA, 3 Phase, 208 x 120/208 Transber

Sq D 15 KVA 600X120/240 Transber, 1 Phase

Siemens SX312A10PL10, 1600 Amp Bus Duct **

Siemens R310APG, 1000 Amp Bus Duct **

Siemens SX312A10PL10, 1200 Amp Bus Duct **

Square D 15 KVA, 1 Ph 600X120/240 Trans **

Square D 225 KVA Transber, 3 Phase, 480 x 240 Volt

Sorgel/Square D 150 KVA Transber, 600 x 120/208 Volt

MGM 150 KVA Transber, 480 x 240 Volt, 3 Phase

Westinghouse 75 KVA Transber, 600 x 120/208 Volt

REX 50 KVA 1 Phase 575x120/240 Transber

Square D 45 KVA Transber, 3 Phase, 480x480/277 Volt

Federal Pacific 15 KVA 3 Ph 480 X 460Y/126 DRY TRANS 

General Electric 15 KVA, 3 Ph 208X120/208 Transf **

Hammond 15 KVA, 480X120/208 NEMA 3R, 3 Ph Trans**

Hammond 112.5 KVA,3PH 480X120/208 NEMA 3R,Trans **

Hammond 45 KVA,480X120/208 NEMA 3R, 3 Ph Trans **

Hammond 30 KVA,480X120/208 NEMA 3R, 3 Ph Trans **

Hammond 75 KVA,480X120/208 3 ph NEMA 3R Trans **

GE 45 KVA 3PH 208X120/208 Cat #9T23B3093 DRY TRANS 

Cutler Hammer 30 KVA 3PH 480 X 120/208 V48M28T30EE 

Square D 800 Amp I-Line Main Lug Panelboard 

Square D 225 Amp, NQOD Main Lug Panelboard **

ITE CE3-B100, 100 Amp Cordon Circuit Breaker  IN BOX

ITE CE3-B020, 20 Amp Cordon Circuit Breaker * IN BOX

ITE CE3-B030, 30 Amp Cordon Circuit Breaker * IN BOX

ITE HE3-B100, 100 Amp Circuit Breaker * IN BOX*

ITE JL3-T225 Trip Unit * IN BOX*

(5) Buss NOS80 Fuses * IN BOX*

(10) Gould/Shawmutt TR20R Fuses * IN BOX*

(5)Shawmutt TR100R Fuses * IN BOX*

Gould/Shawmut TRS-150R, 150 Amp Fuse **

GE LU70, Lot of 12** High Pressure Sodium Lamp **

ITE FJ3-B225, 225 Amp Circuit Breaker * IN BOX*

Square D EHB34030 Circuit Breaker * SURPLUS*

Square D EHB34015 Circuit Breaker * Surplus*

NEMA 4 Dual 5 HP Pump Control Panel **

Siemens W4242L3225CU, Weatherproof Load Center 

Adalet XCE101408 Explosion Proof Junction Box **

Adalet XCE121208 Explosion Proof Junction Box **

Hoffman A8H12ALP, NEMA 12 Jic Box * SURPLUS*

Weighman N12303012, Nema 12 Enclosure * SURPLUS*

Cooper 225 KVA 3PH 13800 X 120/208 PAD MOUNT