6ES7322-1HH01-9AJ0 集成架
3.矢量控制(VC)方式
矢量控制变频调速的做法是将异步电动机在三相坐标系下的定子电流Ia、Ib、Ic、通过三相-二相变换,等效成两相静止坐标系下的交流电流Ia1Ib1,再通过按转子磁场定向旋转变换,等效成同步旋转坐标系下的直流电流Im1、It1(Im1相当于直流电动机的励磁电流;It1相当于与转矩成正比的电枢电流),然后模仿直流电动机的控制方法,求得直流电动机的控制量,经过相应的坐标反变换,实现对异步电动机的控制。其实质是将交流电动机等效为直流电动机,分别对速度,磁场两个分量进行独立控制。通过控制转子磁链,然后分解定子电流而获得转矩和磁场两个分量,经坐标变换,实现正交或解耦控制。矢量控制方法的提出具有划时代的意义。然而在实际应用中,由于转子磁链难以准确观测,系统特性受电动机参数的影响较大,且在等效直流电动机控制过程中所用矢量旋转变换较复杂,使得实际的控制效果难以达到理想分析的结果。
4.直接转矩控制(DTC)方式
1985年,德国鲁尔大学的DePenbrock教授首次提出了直接转矩控制变频技术。该技术在很大程度上解决了上述矢量控制的不足,并以新颖的控制思想、简洁明了的系统结构、优良的动静态性能得到了迅速发展。该技术已成功地应用在电力机车牵引的大功率交流传动上。 直接转矩控制直接在定子坐标系下分析交流电动机的数学模型,控制电动机的磁链和转矩。它不需要将交流电动机等效为直流电动机,因而省去了矢量旋转变换中的许多复杂计算;它不需要模仿直流电动机的控制,也不需要为解耦而简化交流电动机的数学模型。
5.矩阵式交-交控制方式
VVVF变频、矢量控制变频、直接转矩控制变频都是交?直?交变频中的一种。其共同缺点是输入功率因数低,谐波电流大,直流电路需要大的储能电容,再生能量又不能反馈回电网,即不能进行四象限运行。为此,矩阵式交-交变频应运而生。由于矩阵式交?交变频省去了中间直流环节,从而省去了体积大、价格贵的电解电容。它能实现功率因数为l,输入电流为正弦且能四象限运行,系统的功率密度大。该技术虽尚未成熟,但仍吸引着众多的学者深入研究。其实质不是间接的控制电流、磁链等量,而是把转矩直接作为被控制量来实现的。
MODEL RC-1C VOLTAGE REGULATOR/CONTR?OLLER 400V - 1200V
10 NEW ConMED ELECTROSURGICAL PENCILS W/HOLSTER 130318
IBM BLADECENTER MEDIA TRAY 31R3305 FOR CD/DVD DRIVE USB
QTY 6 NEW PHILIPS 100' CAT5E NETWORK CABLES RJ45 GRAY
KIDDE 83-844908-000 DISCHARGE ADAPTER KIT Co2 SYSTEM
NEW OPW AUTOMATIC UNLEADED FUEL PUMP NOZZLE 11AP-0500
MOTOROLA RAD4010ARB ROOF MOUNT VHF ANTENNA 136-174 MHZ
NEW CASE BULK TonER 26.4 LBS OEM IBM INFOPRINT 4100 1R
NEW CONTACT-O-MAX 5 REMOTE ConTROL HOG/BOAR BREEDING
2 NEW ESTERNA SWIMMING POOL INFLATABLE LOUNGE CHAIRS
QTY 10 NEW GM/SATURN OEM 21000938 4cyl 1.9L AIR FILTERS
GLANCE HC RTD COMMERCIAL GLASS CLEANER 40:1 CONCENTRATE
NEW CASE OF 2 RTD BOTTLES, MAKES 32 GALLONS... CHEAP!!
NEW CASE OF 4,900 DIGI SM90 SCALE LABELS
NEW EVERPURE T7O-BW TASTE & ODOR WATER FILTER CARTRIDGE
FERRAZ PROTISTOR 700V 400A FUSE A 070 URD 32 TTI 0400C
QTY 2 NEW EMERSON RPT25A4 25PR TERMINAL BLOCKS F002685
NEW OEM 2005 FORD THUNDERBIRD CLIMATE ConTROL AC/HEATER
DATACARD DURAGARD CLEAR LAMINATE 565750-001 CP80/CP80+
QTY 36 NEW SELMER 2929 CORK GREASE CLARINET SAXAPHONE
NEW OMC STAINLESS STEEL FLANGE SA/A182F304/F30?4L B16
12 NEW CARLISLE 5 x 24 WASHABLE COTTON DUST MOP HEADS
12 NEW COGNITIVE BLASTER ADVANTAGE LX DLX RIBBONS
BRAND NEW CASE, 4.25 x 3156 (263') P/N 04-00-0028-07
60 PHILIPS E10/E12 2.25V KRYPTON PEN-LIGHT BULBS/LAMPS
40 ELKHART KLEENFIT 1/2 COPPER GAS LINE ELBOW FITTING
NEW GENUINE LUCIDIOM 92350 BLACK IMAGE DRUM FOR EQ-9800
GENUINE LUCIDIOM 92353 YELLOW IMAGE DRUM FOR EQ-9800
NEW HP/COMPAQ BLC7000 407295-001 ON-BOARD ADMIN SLEEVE
NEW CHEVY/GMC COLORADO/CANYON OEM VORTEC 2900 RESONATOR
ALSTOM RED LED AIRFIELD/RUNWAY /TAXI/ RR SIGNAL? LIGHTS
NEW SECURITRON PB3 PUSH TO EXIT BUTTON ConTROL ASSEMBLY
CASE GOJO PRO 5000 ANTIBACTERIAL HAND SOAP REFILLS 2x5L
NEW VALCOM V-9939B MICROHONE ADAPTER UNIT
NEW COOPER WHEELOCK ET70WP WEATHERPROOF STROBE SPEAKER
QTY 5 LEBLANC FRENCH HORN SNAKE BRUSH W/8 VALVE/KEY OIL
NEW HonEYWELL M6410A1029 Cartridge Globe Valve Actuator
500' INTERNAL APPLIANCE WIRE 14AWG 600V SOLID COPPER
QTY 25 ZURN QQ800X 1 FEMALE SWEAT BARB BRASS FITTINGS
NEW CASE 6 CARLISLE 2.7 QT FOOD STORAGE CROCKS W/LIDS
GERBER 41-812 CHROME TRIP LEVER BATHTUB DRAIN KIT
2006/2007 TOYOTA HIGHLANDER HYBRID ENGINE BLOCK HEATER
QTY 4 NEW FINISHPRO 14 DRYWALL HAMMERS HICKORY HANDLE
CASE GOJO MICRELL ANTIBACTERIAL HAND SOAP REFILLS 4x 2L
CASE-3 GOJO FMX-12 LUXURY FOAM HAIR & BODY WASH 5163-03
QTY 6 NEW INDUSTRIAL PACKING/STRAPPI?NG TAPE DISPENSERS
10 GE BIAX T/E ECO 32W 4-PIN FLUORESCENT BULBS GX24Q-3
50 NEW SOUTHCO AdvancedMC MODULE HANDLES P7-M-812-000
12 COGNITIVE BARCODE BLASTER/ ADVANTAGE LX WAX RIBBONS
BRAND NEW CASE, 4.23 x 3156 (263') P/N 04-00-0028-01
Enlarge
10 ROLLS AIRTECH VACUUM BAGGING SEALING TAPE 1/2 x 25'
48 BEIGE CARLISLE 9oz INSULATED BOWLS DESSERT/DIP/SAL?SA
4 NEW SILITE LARGE CANOE SERVING/DECORAT?IVE BOWLS BLACK
5 NEW KIDDE 500° STANDARD RESPonSE THERMO-BULB linkS
5 NEW KIDDE 360° STANDARD RESPonSE THERMO-BULB linkS
12 NEW ACDELCO PF2/ 5575840 DURAGUARD OIL FILTERS