140DDO15310 仁怀县
电流型工作原理是整流电路将电网来的交流电转换成直流电;再经三相桥式逆变电路转变为频率可调的交流电,供给推进电动机,电流型变频器的直流中间环节,采用大电感滤波。
电压型变频器与电流型变频器同属于交一直一交变频器,也由整流器、滤波器、逆变器三部分组成。工作原理也是整流电路将电网来的交流电转换成直流电;再经三相桥式逆变电路转变为频率可调的交流电,供给推进电动机,电压型变频器的直流中间环节采用大电容。
软启动的电压由零慢慢提升到额定电压,这样电机在启动过程中的启动电流,就由过去过载冲击电流不可控制变成为可控制。并且可根据需要调节启动电流的大小。电机启动的全过程都不存在冲击转矩,而是平滑的启动运行。
软启动器(soft starter)是一种集电机软起动、软停车、多种保护功能于一体的新颖电机控制装置,国外称为Soft Starter。它的主要构成是串接于电源与被控电机之间的三相反并联晶闸管及其电子控制电路。运用不同的方法,控制三相反并联晶闸管的导通角,使被控电机的输入电压按不同的要求而变化,就可实现不同的功能。软起动器和变频器是两种不同用途的产品。变频器是用于需要调速的地方,其输出不但改变电压而且同时改变频率;软起动器实际上是个调压器,用于电机起动时,输出只改变电压并没有改变频率。变频器具备所有软起动器功能,但它的价格比软起动器贵得多,结构也复杂得多。电动机软起动器是运用串接于电源与被控电机之间的软启动器,控制其内部晶闸管的导通角,使电机输入电压从零以预设函数关系逐渐上升,直至启动结束,赋予电机全电压,即为软启动,在软起动过程中,电机起动转矩逐渐增加,转速也逐渐增加。
软启器采用三相反并联晶闸管作为调压器,将其接入电源和电动机定子之间。这种电路如三相全控桥式整流电路。使用软启动器启动电动机时,晶闸管的输出电压逐渐增加,电动机逐渐加速,直到晶闸管全导通,电动机工作在额定电压的机械特性上,实现平滑启动,降低启动电流,避免启动过流跳闸。待电机达到额定转速时,启动过程结束,软启动器自动用旁路接触器取代已完成任务的晶闸管,为电动机正常运转提供额 定电压,以降低晶闸管的热损耗,延长软启动器的使用寿命,其工作效率,又使电网避免了谐波污染。软启动器同时还提供软停车功能,软停车与软启动过程相反,电压逐渐降低,转速逐渐下降到零,避免自由停车引起的转矩冲击。
HP OMNIBOOK XE3 13.3" LAPTOP LCD DISPLAY LG LP133X7
HP InfiniBand Dual Port 380299-B21
HP E4208C SCSI DISK MODULE HP 75000 SERIES C
HP E4208C SCSI DISK MODULE HP 75000 SERIES C
HP E4208A SCSI DISK MODULE HP 75000 SERIES C
HP E1697A 155 Mb/s OPTICAL LINE VXI HP 75000 SERIES C
HP E1616A LINE INTERFACE MODULE VXI HP 75000 SERIES C
HP E1610A LINE INTERFACE MODULE VXI HP 75000 SERIES C
HP 433027-03 436151-001 1.86Ghz 1066mhz E5320 Quad Core
HP 313054-B21 HOT PLUG REDUNDANT POWER SUPPLY NEW
HP 10897B LASER AXIS VME BUS BLADE
HITACHI 9200 F1F ConTROL UNIT + DFFM5 FIBRE I/F CARD
Heidenhain EXE 602 D/5-F H3 Amplifier Interpolation Box
GRANVILLE PHILLIPS 9873-100 332103 VGC 009874-104
GRANVILLE PHILLIPS 9857-100 332101 IGC 009843-103
GILAT SKYEDGE IP VSAT DVB 542000 VERSION 3.0
GILAT PC010060 HUB RECEIVER MODULE
GILAT LNB LN-5353-10 KU-BAND PART OF AN-3432-10 NEW
GILAT LNB KU-BAND OPTION A AN-3454-10
GILAT KU-BAND ODU TRANSMITTER ANO950KU ANO 950 KU NEW
GILAT KU-BAND ODU TRANSMITTER AN-0692-10 NJT3003TX
GILAT AN-3470-10 XKU-BAND ODU TRANSCEIVER 2W NJT5061M
GILAT AN-3458-10 C-BAND ODU TRANSCEIVER AN-345810
GILAT AN-3435-10 ODU INSAT C ODU 5 WATT XCVR+ EFI
GILAT AN-3434-10 ODU C-BAND 5 WATT XCVR + LN345010
GILAT AN-3433-10 KU-BAND 2 W ODU TRANSCEIVER NJT5051D
GILAT AN343210 ODU KU 2W XCVR OPTION C + EFI AN-3432-10
GILAT AN-3432-10 KU-BAND ODU TRANSCEIVER NJT5051C
GILAT AN-3429-10 2 W KU-BAND ODU TRANSCEIVER NJT5052D
GILAT AN-3426-10 KU-BAND ODU TRANSCEIVER MAIN UNIT NEW
Gilat AN-0691-10 KU Band ODU Transmitter NJT3003T New
GILAT AN-0036-10 XKU-BAND ODU TRANSMITTER AN0036-10
GENERAL STANDARDS CORP. PMC-SI104-ECI3 BOARD
FUJI ELECTRIC M.C.S. LTD. MCO412A BOARD
FUJI ELECTRIC M.C.S. LTD. MCO411 BOARD
EXABYTE VXA-1i 33/66GB 8MM SCSI TAPE DRIVE 112.00210
EXABYTE MAMMOTH TAPE M2 MODEL TT2000
ERICSSON ROHA219101/1 MODULE PULLED FROM BFD CHASSIS
ERICSSON ROAH219102/1 MODULE PULLED FROM BFD CHASSIS
ERICSSON ROA219651/1 MODULE PULLED FROM BFD CHASSIS
ERICSSON RAYNET TGM MODULE + ERIPOWER PKC 4131 PI DC/DC
ERICSSON PKM4610PIDC/DC ConVERTER MINT LOT OF 19
ERICSSON BMR601014 PWR MODULE PULLED FROM BFD CHASSIS
ERICSSON 2100RU212130 KRC 118 16/1 CELLULAR MODULE
ERICSSON 2100FU1221 KRC 118 17/1 CELLULAR MODULE R2B
ERICSSON / Tellabs MARTIS SXU-C MODULE ROA 117 3001/2
EQUINOX SST-64/128P PCI CARD PN: 910256-1
Emerson Bristol Babcock Pressure Switch 506008-649 ASM
EMC AC POWER SUPPLY FOR EMC CX300 DPE AND DAE NEW
ELSA GLORIA SYNERGY-A8 VIVO CARD PN: KJGP2VIVOPAGP
ELGEMS JUL-99 BCNT PCB000198 PCA000339
ECI TR28T BLADE TR2-8T 882-091
ECI TELECOM ExLINE 2 NTU 2P DT X.21 MODEM
ECI TELECOM BROADGATE nNT-E ROUTER 4x E1 PORTS NEW
DY 4 Systems DMV-783 901163-603 DY-4 DMV783
DY 4 Systems DMV-739 900816-005 DY-4 DMV739
DTT R2000 - ACCESS DATANG SU-RA-3.5A1 + SU-NI-1D-3.5A1
DPT PM3755U2B 3 Channel LVD Raid w/DPT SX4050 SX4055U2
DIVERSIFIED TECHNOLOGY 651400975 ISA CARD
Disposable Pens Bristol Babcock Recorder 375985018 __B8
DIGITAL DECSERVER 900TM 76-200-0001 W/ DECHUB ONE
DIGITAL DECSERVER 700 DSRVM-ZC
DIGIBOARD DIGICHANNEL BOX DUAL IMAC+ POWER SUPPLY
DIGI CLASSICBOARD 4 16654 NCR 77000649
DESCHUTES CORPORATION SG100 670-0030-00 MAINframe BOARD
DESCHUTES CORPORATION OCTUPOLE DRIVER 670-0100-01
DELL SEAGATE STU42001LW 100/200GB TAPE W/ 4 CARTRIDGES
Dell PE18551 BMX-MB MC662 DRAC Panel Assy PC471
DEC VT525 A6 DIGITAL COLOR TERMINAL base TESTED VT 525
DATAKINETICS SPCI4/02 SS7 4 PORTS SEPTEL PCI CARD SPCI4
DATACUBE MAX VIDEO 20 260-0599 VME BOARD 080-0599-03
DATACOM LAN SWITCH MX8100BTsl-1071
DATA SWITCH 9045 9045-15LL2DST
DATA GENERAL VSC/3I BLADE VSC-3I 005039452
DALSA CORECO PC-CAMlink LNK4481 PCCAMlink
DALSA CORECO PC-CAMlink LNK3108 PCI frame GRABBER
DALSA CORECO iMAGING OC-B2PO-CVORB
DA PS 3-2 DXP 2491 LENS
CYCLONE MICROSYSTEMS PCI913 REV A 270-0913
CRR 804 CRR804/5 REV B ISA CARD
CROSSBEAM C25 Dual Xeon 3.2GHz 2G RAM NO HDD
ConDOR CPCI-204-1203 P.S CISCO IP/VC 3540 SCOPIA 400
ConDOR CPCI-204-1203 D.C POWER SUPPLIES CPCI 204
COMPUTER RECOGNITION SYSTEMS VME OVERLAY 8946-0001
COMPUTER RECOGNITION SYSTEMS VME BOARD 8937-0000
COMPUTER RECOGNITION SYSTEMS VME BOARD 8815CX528
COMPUTER RECOGNITION SYSTEMS VME BOARD 8805DP862
COMPUTER RECOGNITION SYSTEMS VIDIO BOARD 10779
COMPUTER RECOGNITION SYSTEMS LCS BOARD 1520-1000
COMPUTER RECOGNITION SYSTEMS 8843CC413 EDGE DETECTOR
COMPAQ ALPHASERVER DS10 DA-PB10A-AC
COMPAQ 153618-002 20/40GB TAPE 169024-001 EOD006 MINT
Compaq 153612-006 50/100GB AIT-2 SCSI Tape
COMPACT PCI 100P172820 120P243641 BLADE NEW
COMPACT PCI 100P172820 120P243641 BLADE
COMMATCH GVC-III-480 PVRB 672 BLADE
COHU Camera Control Unit 6712-2000
COHERENT EC-6321A-AOBMA CARD EC-6321A-25 REV A5
COGNEX 4400 BLADE VM13C+ VM13B VME-4438-1MX
CNT LCP4LX PROCESSOR MODULE 20501191 CHL-NAU 5401
CNT LCP4E-40 PROCESSOR MODULE 20501490 CHL-NAU 5401
CNT HSSI DTE INTERFACE MODULE 20501152 CHL-NAU 5401
CNT HSP3 INTERFACE MODULE 20501316 CHL-NAU 5401
CNT EIM3 INTERFACE MODULE 20501330 CHL-NAU 5401
CNT EDC1 INTERFACE MODULE 20501410 CHL-NAU 5401