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1、皮带机输送机中英文对照外文翻译文献中英文资料翻译 中文: 带式输送机及其牵引系统 在运送大量的物料时，带式输送机在长距离的运输中起到了非常重要的竞争作用。输送系统将会变得更大、更复杂，而驱动系统也己经历了一个演变过程，并将继续这样下去。如今，较大的输送带和多驱动系统需耍更大的功率，比如3驱动系统需耍给输送带750KW(成庄煤矿输送机驱动系统的要求)。控制驱动力和加速度扭矩是输送机的关键。一个高效的驱动系统应该能顺利的运行，同时保持输送带张紧力在指定的安全极限负荷内。为了负载分配在多个驱动上，扭矩和速度控制在驱动系统的设计中也是很重要的因素。由于输送机驱动系统控制技术的进步，目前更多可靠的低成本
2、和高效驱动的驱动系统可供顾客选择1 1带式输送机驱动 1. 1带式输送机驱动方式 全电压启动 在全电压启动设计中，带式输送机驱动轴通过齿轮传动直接连接到电机。直接全压驱动没有为变化的传送负载提供任何控制，根据满载和空载功率需求的比率，空载启动时比满载可能快3-4倍。此种方式的优点是:免维护，启动系统简单，低成本，可靠性高。但是，不能控制启动扭矩和最大停止扭矩。因此，这种方式只用于低功率，结1 构简单的传送驱动中。 降压启动 随着传送驱动功率的增加，在加速期间控制使用的电机扭矩变得越来越重要。由于电机扭矩是电压的函数，电机电压必须得到控制，一般用可控硅整流器(SCR构成的降压启动装置，先施加低电
3、压拉紧输送带，然后线性的增加供电电压直到全电压和最大带速。但是，这种启动方式不会产生稳定的加速度，当加速完成时，控制电机电压的SCR锁定在全导通，为电机提供全压。此种控制方式功率可达到750kW。 绕线转子感应电机 绕线转子感应电机直接连接到驱动系统减速机上，通过在电机转子绕组中串联电阻控制电机转矩。在传送装置启动时，把电阻串联进转子产生较低的转矩，当传送带加速时，电阻逐渐减少保持稳定增加转矩。在多驱动系统中，一个外加的滑差电阻可能将总是串联在转子绕组回路中以帮助均分负载。该方式的电机系统设计相对简单，但控制系统可能很复杂，因为它们是基于计算机控制的电阻切换。当今，控制系统的大多数是定制设计来
4、满足传送系统的特殊规格绕线转子电机适合于需要400kVV以上的系统。 直流(DC)电机 大多数传送驱动使用DC并励电机，电机的电枢在外部连接。控制DC驱动技术一般应用SCR装置，它允许连续的变速操作。DC驱动系统在机械上是简单的，但设计的电子电路，监测和控制整个系统，相比于其他软启动系统的选择是昂贵的，但在转矩、负载均分和变速为主要考虑的场合，它又是一个可靠的，节约成本的方式。DC电机一般使用在功率较大的输送装置上，包括需耍输送带张力控制的多驱动系统和需要宽变速范围的输送装置上。 1.2液力偶合器 流体动力偶合器通常被称为液力偶合器，由三个基本单元组成:充当离心泵的叶轮，推进水压的涡轮和装进两
5、个动力部件的外壳。流体从叶2 轮到涡轮，在从动轴产生扭矩。由于循环流体产生扭矩和速度，在驱动轴和从动轴之间不需要任何机械连接。这种连接产生的动力决定于液力偶合器的充液量，扭矩正比于输入速度。因在流体偶合中输出速度小于输入速度，其间的差值称为滑差，一般为1%-3%。传递功率可达几千千瓦。 固定充液液力偶合器 固定充液液力偶合器是在结构较简单和仅具有有限的弯曲部分的输送装置中最常用的软启动装置，其结构相对比较简单，成本又低，对现在使用的大多数输送机能提供优良的软启动效果。 可变充液液力偶合器 也称为限矩型液力偶合器。偶合器的叶轮装在AC电机上，涡轮装在从动减速器高速轴上，包含操作部件的轴箱安装在驱
6、动基座。偶合器的旋转外壳有溢出口，允许液体不断地从工作腔中流出进入一个分离的辅助腔，油从辅助腔通过一个热交换器泵到控制偶合器充液量的电磁阀。为了控制单机传动系统的启动转矩，必须监测AC电机电流给电磁阀的控制提供反馈。可变充液液力偶合器可使用在中大功率输送系统中，功率可达到数千千瓦口这种驱动无论在机械，或在电气上都是很复杂的，其驱动系统成本中等。 勺管控制液力偶合器 也称为调速型液力偶合器。此种液力偶合器同样由三个标准的液力偶合单元构成，即叶轮、涡轮和一个包含工作环路的外壳。此种液力偶合器需要在工作腔以外设置导管(也称勺管)和导管腔，依靠调节装置改变勺管开度(勺管顶端与旋转外壳间距)人为的改变工
7、作腔的充液量，从而实现对输出转速的调节。这种控制提供了合理的平滑加速度，但其计算机控制系统很复杂。勺管控制液力偶合器可以应用在单机或多机驱动系统，功率范围为150kW-750kW。 1. 3变频控制(VFC) 3 变频控制也是一种直接驱动方式，它具有非常独特的高性能。VFC装置为感应电机提供变化的频率和电压，产生优良的启动转矩和加速度。VFC设备是一个电力电子控制器，首先把AC整流成DC，然后利用逆变器，再将DC转换成频率、电压可控的AC. VFC驱动采用矢量控制或直接转矩控制(DTC)技术，能根据不同的负载采用不同的运行速度。VFC驱动能根据给定的S曲线启动或停车，实现自动跟踪启动或停车曲线
8、。VFC驱动为传送带启动提供了优良的速度和转矩控制，也能为多机驱动系统提供负载均分。VFC控制器可以容易地装在小功率输送机驱动上。过去在中高电压使用时，VFC设备的结构由于受电力半导体器件的电压额定值限制而变得很复杂，中高电压的变速传动常常使用低压逆变器，然后在输出端使用升压变压器，或使用多个低压逆变器串联来解决。与简单的器件串联连接的两电平逆变器系统比较，由于串联器件之间容易均压以及输出端可以有更好的谐波特性，三电平电压型PWI逆变器系统在数兆瓦工业传动中近年来获得了越来越多的应用。由三台750kW/ 2.3kv的这种逆变器构成的VFC系统已经成功安装在成庄煤矿长2. 71m二的带式输送机驱
9、动系统中。 2使用IGBT的中性点箱位三电平逆变器 由于串联器件电压均分容易，器件每次开关的dv/dt低以及输出端出色的谐波品质，三电平电压型逆变器在大功率传动应用中变得越来越流行。高压IGBT(HV-IGBT)的出现使得应用三电平中性点箱位原理的中高压逆变器设计有了更大的应用范围。这种逆变器目前可以实现从2. RV到4. 16kV全范围的应用。HV-IGBT模块串联可使用在3. RV和4. 16kV的设备。2. AV逆变器每个开关只需要一个HV-IGBT2,3。 2.1主功率逆变电路 4 主功率逆变电路用三电平中点箱位电压型逆变器实现，可以满足中高压交流传动应用的需要。与两电平电压型逆变器相
10、比，三电平中点箱位电压型逆变器提供三个电压级别给输出端，对于同样的输出电流品质，开关频率可降低到原来的1/4,开关器件的电压额定值可减小到原来的1/2，附加到电机上的额外的瞬态电压应力也可能减少到原来的1/2。 三电平中点箱位电压型逆变器的开关状态可归纳于表1，U，V和W分别表示三相，P, N和G是直流母线上的三个点。例如，当开关S1u和S2u闭合时，U相处于状态P(正母线电压)，反之，当开关S3u和S4U闭合时，U相处于状态n(负母线电压)。在中性点箱位时，该相在o状态，这时根据相电流极性的正负，或者是S2U导通或者是S3U导通。为了保证中性点电压平衡，在o点被注入的平均电流应该是零。 2.
11、2输入端变流器 为通常使用12脉冲二极管整流器给直流环节电容器充电，在输入端引入的谐波是很小的。若对输入谐波有更高的要求，可以使用24脉冲二极管整流器作为输入变流器。对于需要有再生能力的更高级应用，可以用一个有源输入变流器取代二极管整流器，这时输入整流器与输出逆变器为同一结构。 2.3逆变器控制 电机控制感应电机的控制可以使用转子磁场定向矢量控制器实现，通过使用PWM调制器完成了恒转矩区和高速弱磁区的控制。图2为间接矢量控制框图图中指令磁通甲r是速度的函数，反馈速度和前馈滑差控制信号川赫目加。对相加结果的频率信号积分，然后产生单位矢量(cos e和sinOe )，最后通过矢量旋转器产生电压V角
12、控制PWM调制器。 5 PWM调制器 该调制器实际上是把空间矢量调制概念扩展到三电平逆变器。其基本原理是三电平PWM调制器使用两个参考波认Ur1和Ur2，但只使用一个三角波。它以一种优化方式确定每一次开关时刻。 产生的谐波尽可能的小，使用尽可能低的开关频率以最小化开关损耗;可将零序成分加到每一个参考波里以便最大化基波电压。作为一个附加的自由度，参考波与三角波的相对位置可改变，这可以用于直流环节中点的电流平衡。 3 测试结果 三个750kW/ 2. 3V三电平逆变器在成庄煤矿2. 7km.长带式输送机驱动系统成功安装之后，对整个变频传动系统(VFC)的性能进行了测试，测试结果显示出使用VFC控制
13、系统的带式输送机的优良特性。图3为测试结果波形。由图看出，曲线1显示受控带速，带速呈S形曲线形状，曲线2、3分别表示电流和扭矩，曲线4显示带张力。从图中可以发现，带张力的波动范围很小，所有检测结果显示出带式输送机驱动系统令人满意的特性。 4结论 近年来输送机驱动控制技术的进步已更为可靠，符合低成本效益和高效驱动的驱动系统为用户提供了选择。在这些选择中，可变频率控制(VFC)的方法显现出在将来长距离输送中带式输送机扮演了重要的角色。使用高压工GBT的中点嵌位三电平逆变器本身可以提供电机终端所需的供电中高压，使变频控制的应用更为简单。通过成庄煤矿2. 7km长带式输送机中采用的中点嵌位三电平逆变器
14、变频调速(VFC)控制系统的测试结果表明，采用BV-IGBT的中点嵌位三电平逆变器以及使用转子磁场矢量控制策略的感应电机变频传动，使带式输送机驱动系统具有非常优秀的性6 能，显示出良好的应用前景。 英文 Belt Conveying Systems Development of driving system Among the methods of material conveying emploved, belt conveyors play a very imporient part in the reliable carrying of material over long distan
15、ces at competitive cost. Conveyor systems have become larger and more complex and drive systems have a l so been going through a process of evolution and will continue to do so. Nowadays, bigger belts require more power and have brought the need for larger individual drives as well as multiple drive
16、s such as 3 drives of 750 kW for one belt(this is the case for the conveyor drives in Chengzhuang Mine). The ability to control drive acceleration torque is critical to belt conveyors performance. A efficient drive system should be able to provide smooth, soft starts while maintaining belt tensions
17、within the specified safe limits. For load sharing on multiple drives. torque and speed control are also considerations in the drive systems design. Due to the advances in conveyor drive control technology, at present many more reliable. Cost-effective and performance- driven conveyor drive systems
18、covering a wide range of power are available for 7 customers choices1. 1 Analysis on conveyor drive technologies 1. 1 Direct drives Full-voltage starters. With a full-voltage starter design, the conveyor head shaft is direct-coupled to the motor through the gear drive. Direct full-voltage starters a
19、re adequate for relatively low-power, simple- Profile conveyors. With direct full-voltage starters. no control is provided for various conveyor loads and. depending on the ratio between full- and no-load power requirements, empty starting times can be three or four times faster than full load. The m
20、aintenance-free starting system is simple, low-cost and very reliable. However, they cannot control starting torque and maximum stall torque; therefore. they are limited to the low-power, simple-profile conveyor belt drives. Reduced-voltage starters. As conveyor power requirements increase,controlli
21、ng the applied motor torque during the acceleration period becomes increasingly important. Because motor torque is a function of voltage, motor voltage must be controlled. This can be achieved through reduced-voltage starters by employing a silicon controlled rectifier (SCR). A common starting metho
22、d with SCR reduced-voltage starters is to apply low voltage initially to take up conveyor belt slack. and then to apply a timed linear ramp up to full voltage and belt speed. However, this starting method will not produce constant conveyor belt acceleration. When acceleration is complete. the SCRs,
23、which control the applied voltage to the electric motor. are locked in full conduction, providing full-line 8 voltage to the motor. Motors with higher torque and pull -vp torque, can provide better starting torque when combined with the SCR starters, which are available in sizes up to 750 KW. Wound
24、rotor induction motors. Wound rotor induction motors are connected directly to the drive system reducer and are a modified configuration of a standard AC induction motor. By inserting resistance in series with the motors rotor windings. the modified motor control System controls motor torque. For co
25、nveyor starting, resistance is placed in series with the rotor for low initial torque. As the conveyor accelerates,the resistance is reduced slowly to maintain a constant acceleration torque. On multiple-drive systems. an external slip resistor may be left in series with the rotor windings to aid in
26、 load sharing .the motor systems have a relatively simple a design.However,the control systems for these can be highly complex, because they are based on computer control of the resistance switching. Today, the majority of control systems are custom designed to meet a conveyor systems particular spe
27、cifications. Wound rotor motors are appropriate for systems requiring more than 400KW. DC motor. DC motors. available from a fraction of thousands of KW，are designed to deliver constant torque below base speed and constant KW above base speed to the maximum allowable revolutions per minute (r/min).
28、with the majority of conveyor drives, a .DC shunt wound motor is used. Wherein the motors rotating armature is connected externally. The most common technology for controlling DC drives is a SCR device. which allows 9 for continual variable-speed operation. The DC drive system is mechanically simple
29、, but can include complex custom-designed electronics to monitor and control the complete system. this system option is expensive in comparison to other soft-start systems. but it is a reliable, cost-effective drive in applications in which torque,load sharing and variable speed are primary consider
30、ations. DC motors generally are used with higher-power conveyors, including complex profile conveyors with multiple-drive systems, booster tripper systems needing belt tension control and conveyors requiring a wide variable-speed range. 1. 2 Hydrokinetic coupling Hydrokinetic couplings, commonly ref
31、erred to as fluid couplings. are composed of three basic elements; the driven impeller, which acts as a centrifugal pump; the driving hydraulic turbine known as the runner and a casing that encloses the two power components. Hydraulic fluid is pumped from the driven impeller to the driving runner, p
32、roducing torque at the driven shaft. Because circulating hydraulic fluid produces the torque and speed, no mechanical connection is required between the driving and driver shafts.The power produced by this coupling is based on the circulated fluids amount and density and the torque in proportion to
33、input speed. Because the pumping action within the fluid coupling depends on centrifugal forces. the output speed is less than the input speed. Referred to as slip. this normally is between 1% and 3%. Basic hydrokinetic couplings are available in configurations from fractional to several thousand KW
34、. Fixed-fill fluid couplings. Fixed-fill fluid couplings 10 are the most commonly used soft-start devices for conveyors with simpler belt profiles and limited convex/concave sections. They are relatively simple,low-cost,reliable,maintenance free devices that provide excellent soft starting results t
35、o the majority of belt conveyors in use today. Variable-fill drain couplings. Drainable-fluid couplings work on the same principle as fixed-fill couplings. The couplings impellers are mounted on the AC motor and the runners on the driven reducer high-speed shaft. Housing mounted to the drive base en
36、closes the working circuit. The couplings rotating casing contains bleed-off orifices that continually allow fluid to exit the working circuit into a separate hydraulic reservoir. Oil from the reservoir is pumped through a heat exchanger to a solenoid-operated hydraulic valve that controls the filli
37、ng of the fluid coupling. To control the starting torque of a single-drive conveyor system, the AC motor current must be monitored to provide feedback to the solenoid control valve. Variable fill drain couplings are used in medium to high-kw conveyor systems and are available in sizes up to thousand
38、s of kw.The drives can be mechanically complex and depending on the control parameters. the system can be electronically intricate. The drive system cost is medium to high,depending upon size specified. Hydrokinetic scoop control drive. The scoop control fluid coupling consists of the three standard
39、 fluid coupling cmponents: a driven impeller, a driving runner and a casing that encloses the working circuit. The casing is fitted with fixed orifices that bleed a predetermined amount of fluid into a reservoir. When the scoop tube is fully extended into 11 the reservoir, the coupling is 100 percen
40、t filled. The scoop tube, extending outside the fluid coupling, is positioned using an electric actuator to engage the tube from the fully retracted to the fully engaged position. This control provides reasonably smooth acceleration rates. to but the computer-based control system is very complex. Sc
41、oop control couplings are applied on conveyors requiring single or multiple drives from 150KWto 750KW. 1. 3 Variable-frequency control(VFC) Variable frequency control is also one of the direct drive methods. the emphasizing discussion about it here is because that it has so unique characteristic and
42、 so good performance compared with other driving methods for belt conveyor. VFC devices Provide variable frequency and voltage to the induction motor, resulting in an excellent starting torque and acceleration rate for belt conveyor drives. VFC drives. available from fractional to several thousand (
43、kW)，are electronic controllers that rectify AC line power to DC and, through an inverter, convert DC back to AC with frequency and voltage control. VFC drives adopt vector control or direct torque control(DTC)technology, and can adopt different operating speeds according to different loads. VFC driv
44、es can make starting or stalling according to any given S-curves realizing the automatic track for starting or stalling curves. VFC drives provide excellent speed and torque control for starting conveyor belts. and can also be designed to provide load sharing for multiple drives. easily VFC controll
45、ers are frequently installed on lower-powered convey- or drives, but when used at the range of medium-high voltage in the past. the structure of VFC controllers becomes very complicated due to the limitation of voltage rating of power semiconductor 12 devices, the combination of medium-high voltage
46、drives and variable speed is often solved with low-voltage inverters using step-up transformer at the output, or with multiple low-voltage inverters connected in series. Three-level voltage-fed PWM converter systems are recently showing increasing popularity for multi-megawatt industrial drive appli
47、cations because of easy voltage sharing between the series devices and i叩roved harmonic quality at the output compared to two-level converter systems With simple series connection of devices. This kind of VFC system with three 750 kW /2. AV inverters has been successfully installed in ChengZhuang Mi
48、ne for one 2. 7-km long belt conveyor driving system in following the principle of three-level inverter will be discussed in detail. 2 Neutral point clamped(NPC)three-level inverter using IGBTs Three-level voltage-fed inverters have recently become more and more popular for higher power drive applic
49、ations because of their easy voltage sharing features. lower dv/dt per switching for each of the devices, and superiorharmonic quality at the output. The availability of NV-IGBTs has led to the design of a new range of medium-high voltage inverter using three-level NPC topology. This kind of inverter can realize a whole ran
