RWD62 温控器
低压通用变频输出电压为380~650V,输出功率为0.75~400kW,工作频率为0~400Hz,它的主电路都采用交—直—交电路。其控制方式经历了以下四代。
正弦脉宽调制(SPWM)控制方式
其特点是控制电路结构简单、成本较低,机械特性硬度也较好,能够满足一般传动的平滑调速要求,已在产业的各个领域得到广泛应用。但是,这种控制方式在低频时,由于输出电压较低,转矩受定子电阻压降的影响比较,使输出大转矩减小。另外,其机械特性终究没有直流电动机硬,动态转矩能力和静态调速性能都还不尽如人意,且系统性能不高、控制曲线会随负载的变化而变化,转矩响应慢、电机转矩利用率不高,低速时因定子电阻和逆变器死区效应的存在而性能下降,稳定性变差等。因此人们又研究出矢量控制变频调速。
电压空间矢量(SVPWM)控制方式
它是以三相波形整体生成效果为前提,以逼近电机气隙的理想圆形旋转磁场轨迹为目的,一次生成三相调制波形,以内切多边形逼近圆的方式进行控制的。经实践使用后又有所改进,即引入频率补偿,能速度控制的误差;通过反馈估算磁链幅值,低速时定子电阻的影响;将输出电压、电流闭环,以动态的精度和稳定度。但控制电路环节较多,且没有引入转矩的调节,所以系统性能没有得到根本改善
Volt-Doctor Voltage Continuity Tester Gardner Bender Electrical Tools GVC-300
Voltage & Continuity Tester Garner Bender Volt-Doctor GVC 300 6-600 V AC/DC Test
VISION PLATE BENDER WITH 4 PUNCHES MODEL VIPB II GR-010
Virax® Motorised 3/8in.-2in Gas Hydraulic Bender 230v AC Sliding Cheek 240843
Vinyl Electrical Tape, 20' X 1/2", Assorted Colors, 5-Pack Gardner Bender
VintageT&B Steeltubes Bender # 4195 1/2" --4+1
Vintage Tubing Bender
Vintage Tube Bender Maker unknown
Vintage Tube Bender -Handy Holsclaw Bros Model B4 R1-10-2
Vintage T&B Steeltubes Conduit Bender # 4196 3/4" With 35" Threaded Handle
VINTAGE T & B STEEL TUBE BENDER - FOR 3/4" TUBING
Vintage Parker Appliance Co. Hand Tube Bender 3/8" No. 6 Beauty!
VINTAGE PARKER APPLIANCE 1/4" HAND BENDER FORGED STEEL O.D. TUBE BENDER NO.4
VINTAGE PARKER APPLIANCE 1/4" HAND BENDER
VINTAGE Mount PIPE BENDER , MADE in USA- Pipes 1/8-3.5"
Vintage Lot Of 2 Gould Spring Bender For Soft Tubing 3/8" & 1/2" Old Stock
VINTAGE LEW MATERIAL COMPANY BENDER - FOR BOTH 1/2" & 3/4" RIDGID TUBING
Vintage Lew Fitting Co. Electrical Conduit Pipe Bender~No. 222A~Collectible Tool
vintage Imperial # 364-F Tubing Bender For 3/8” OD Tubing MADE IN THE USA
Vintage Henderson EMCO Bender EL2 3/4" Pipe Electrical Bender
VINTAGE CRAFTSMAN 9-55411 6 PIECE TUBE BENDER SET IN GREAT CONDITION U.S.A.
Vintage BENFIELD Model 1472 Conduit Pipe Bender 1/2" Electronite USA MADE
Vintage Assorted 90 Degree Pipe Conduit Benders JA Richards Lew Rigid Old Tools
Vintage Appleton Benfield Iron Metal Bender HB-7 3/4" EMT Or 1/2" Rigid
Vintage Allen 525 Manual Hand Pipe Tubing Bender Steel City
Vintage 1956 "The Bending System For Republic Inch-Marked Electrunite EMT"
Vintage 1/2" Pipe Bender
Vintage 1/2" & 3/4" Thinwall Conduit Bender
VanLine K120.1050 KS Mini Pipe Bender
Uvb Cable Clamp, 3/8", 15/Bag, Black Gardner Bender Staples PPC-1538UVB
U-Turn Tube Bender Digital Read Out for JD2 Model 32 "Parts Kit"
U-Turn Tube Bender Digital Read Out for JD2 Model 32 "Completly Assembled"
U-Turn Tube Bender Digital Read Out for JD2 Model 3, Pro Tools, JMR "Parts Kit"
U-Turn Bender Digital Read Out for JD2 Model 3, Pro Tools, JMR "Fully Assembled"
, Greenlee 755 Hydraulic Hand Pump for Greenlee Benders
, Greenlee 1801 Mechanical Bender for 1-1/4",, 1-1/2" IMC and Rigid Conduit
Whitney Jensen Flat Bar Bender-
Rigid B-1677 Pipe Bender 1/2" E.M.T. GUC Made in USA BIN Free Shipping P2
Reed Power Roll Bender - Initial Pinch
GREENLEE 851 BENDER-PVC 4"
GREENLEE 5014265 884 885 4" IPS CONDUIT BENDER BENDING SHOE
Greenlee 4" Shoe for 881 Conduit Bender 26305
Greenlee 3" Shoe for 855 Conduit Bender
Greenlee 2-1/2" Shoe for 855 Conduit Bender
ENERPAC PIPE BENDER PARTS ***MAKE OFFER***
EAGLE BA-50 CNC ANGLE ROLL TUBE BENDER 2" PIPE CAP. CAD DXF FILES
3/4" (20mm) NB, 26.9mm O/D Hydraulic Tube Pipe Bender Former
1" (25mm) NB, 33.7mm O/D Hydraulic Tube Pipe Bender Former
Unterspannungsrelais Bender SUR 353
Unterspannungsrelais Bender SUA 140 No.932559 Under Voltage Relay
Uniweld 70021 Spring Tube Bender for 3/4-Inch OD Soft Copper and Aluminum
Uniweld 70021 Spring Tube Bender for 3/4-Inch OD Soft Copper and Aluminum
Universal Rod Bender 11" Orthopedic Instruments
UNIVERSAL ROD BENDER 11" Orthopedic Instruments
Universal Mounting Base, 1" L X 1" W, 5/Bag GB-Gardner Bender Wire Clamps/Clips
Universal Heavy Duty Bender for Squares Rounds 360 degree bending range
Unitek Welding System Uniflow Supply Spot Welder 3-028-04 500W Power Supply
Ugly'S Electrical Reference Book Gardner Bender Reference Materials ERB-UG
UF Splice Kit 8", 14-8 AWG, Gardner Bender, Made in USA!!!
UCC UC-DC-42 PB BORE DRIVE COUPLING ***NIB***
Überstromrelais Bender CSE 141 Relais
Überstrom Trafotemperatur Relais Overload Relay BENDER LSE470
Type 110 Replacement Punch Down Blade GB-Gardner Bender PDB-3110 Black
Two Boxes 100 pcs Gardner Bender Electrical Nail Straps NS-75 3/4 -inch size
Turtle-Bone Plate Bender 3mm & 4mm,Surgical orthopedic Instruments(High Quality)
Tubing Tube Bender Aluminum Copper and Steel 1/