1、 毕业设计(外文翻译)题 目永磁同步电动机直接转矩控制系统 系 (院) 自动化系 专 业 电气自动化技术 学生姓名 学 号 指导教师 职 称 2011年 6月 15日word文档 可自由复制编辑Always magnetic belt synchro motor direct torque control system0 - prefaceSynchro motor because of having power factor higher -, run - timeefficiency higher -, stability good, the revolving speed Heng se
2、ttles to wait a merit, is extensively been applied to industrial production amid.The startingfault that acquaints with synchro motor, and debugging in time, all have important meaning to the motor and the production systemses.By wayof energy in time, accurate debugging and transaction fault, have to
3、vsthefamiliar fault progress of the synchro motor in detail analytical!1 - Familiar fault1.1- The synchro motor after switching on electricity the incapability starts The synchro motor after starting the incapability run - time generally has the reason of severals as follows:(1) Power supply voltage
4、 over low.Because at the square of voltage, the starting torque direct proportion of synchro motors the voltage of power supply over make low the starting torque of synchro motor significantly the droop is lower than load troque, can not start thus and want to raise vs this power supply voltage to e
5、nlarge the starting torque of dynamo.(2) The fault of motor.Check motor settle, the rotor winding had no short circuit, open circtui, open soldering and link bad etc. fault, these the faults will make the dynamo can not start to create starting of rating of intensity of magnetic field, make thus the
6、 dynamo can not start;Checking the motor bearing has already had no failure, the port cap has have no loose, if bearing failure port shroud loose, result in bearings down sinking, mutually rub with stator iron core, result in thus dynamos canning not start, vs settle the rotor fault can be shaken ta
7、ble with the low tension, gradually click to check to seek a fault condition and adopt homologous treatment;The countersgaft accepts and carries to shroud a loose condition and all wants a pan car before driving each time and sees motor rotor whether slewing is vivid, if bearing or shaft kiowatt dam
8、age and replace in time.(3) The control device breaks down.This kind of faults are mostly the d.c. output voltage of the windings of Li magnetic belt to adjust not appropriate or dont output, result in the stator current of motor over big, cause the motor conduct electricity the run make or the losi
9、ng of dynamo magnetic belt run - time.Should check whether output voltage current and its waveform that the Li magnetic belt equips is normal at this time, the Rong breaks whether the machine Rong breaks, the contact is bad;Whether circuit board plug-in puts prison or alignment;Check loop resistance
10、, put out whether crystal gate tube of magnet burns out or brokes through.(4) Mechanical trouble.Such as be dragged along a dynamic machinery to block, result in motor incapabilitys starting, the rotor that moves motor in response to the pan at this time sees whether the slewing is vivid, machinery
11、burden whether existence fault1.2- The synchro motor incapability leads long into synchronization. Synchro motor in common use law of nonsynchronous starting, throw in Li magnetic belt when the motor rotor revolving speed hits synchronous revolving speed of 95%, make it leads long into synchronizati
12、on.The synchro motor incapability leads long into synchronous reason as follows:(1) The Li magnetic belt winding short circuit.Because the winding of Li magnetic belt, existence short circuit breaks down, as a result makes motor able to stabilize run - time but incapability and lead long into synchr
13、onization while being lower than synchronous revolving speed.Check to seek the Li magnetic belt winding short circuit, can open into low - tension(about the 30 Vs) in the rotor derivation on - line, put on the magnetic poles surface with a hand work steel saw, pursue inspection magnetic poles, if vi
14、brating is violent, explain the magnetic poles to have no short circuit on steel saw of the magnetic poles surface, if the vibrating of saw blade micro or dont flap, explain the magnetic poles short circuit.After unloading the magnetic poles, check the fault to click, is short-circuit degree, adopt
15、local to mend or re- round to make.(2) Power supply voltage over low.Power supply voltage over low, result in the strong Li link of the device of Li magnetic belt incapability working, make the motor incapability lead long into synchronization thus, the concrete way is to raise power supply voltage
16、appropriately.(3) The fault of Li magnetic belt device.Such as throw Li over speedy(namely throw in Li magnetic belt, motor rotor revolving speed over low), will make the motor can not lead long into synchronization, should check to throw if the Li link exists fault at this time.If Li magnetic belt
17、device fault, the outputs current is lower than a rating value, cause the electricity magnetic troque of dynamo over small but can not lead long into synchronization, at this time in response to scrutiny Li magnetic belt device of throw Li link and phase - shifting link, waveform use oscillograph to
18、 check to throw Li link and phase - shifting link, should also check and put out magnetic belt link and put out crystal gate of magnetic belt whether tube discovers a question as usual, handle in time, if the incapability handles in time, by way of the energy quickly restore capacity, should replace
19、 to provide for use circuit board.1.3- Brush and compress tightly spring and gather to give or get an electric shock ring fault.The brush leads short and compresses tightly spring press scarcity and make brush and gather to give or get an electric shock ring of indirectly touch badly, thus generate
20、spark or arc electric, arc electric or spark to on the other hand and easily spark short circuit, will make arc electric burn on the other hand shorter, spark open circtui thus, result in Li magnetic belt device only the Li magnetoelectricity press but have no Li magnetoelectricity streaming;Compres
21、s tightly spring ageing lapse, make brush and gather to give or get an electric shock ring of indirectly touch badly, effect the starting of motor thus;Gather to give or get an electric shock a ring surface to there is grease stain and scar or slot scar, will make brush and gather to give or get an
22、electric shock ring of indirectly touch badly, generate spark, spark further burn gather to give or get an electric shock ring, will also make gnd short-circuit, the spark effects the starting of motor thus.For gather to give or get an electric shock ring superficial grease stain, can wipe to clean
23、with the acetone; For thin trace, use many fettle shagging rings of sandpapers surface, is ring surface roughness to hit R1.6 ums, if the slot scar obviously needs to get on the car bed transform, truning, enter amount of knife to take every time 1 mm as proper, in the 1-1.5 ms/s, the truning speed
24、controls roughness hits of the ums of R1.5-1.8 and becomes bad anti to finally polish with the sandpaper 2-3 times over the 0.05 mms.1.4- The damper winding breaks down.The damper winding of synchro motor rotor is provided for synchro motor starting to use and wipe - out run - time at the same time
25、amid spark because of loading to change of out of step osc.Start the damper winding in the process to incise the magnetic field of stator revolution but induced very big starting current in the synchro motor, so the big current by all means will result in damping hair thermal expansion, under the no
26、rmal condition because of starting time short, the damper winding starting is behind soon will cool off, but block up revolution in the motor, lack phase, start the super - in time to lengthways wait a condition down, if dont shut down in time, will result in the damping take off soldering to split
27、etc. condition.The damper winding is weaker link in the synchro motor parts, the damper winding familiar fault has:The damping takes off soldering and split, the damping ring discharges wildfire, damping ring the strain is serious.These faults will effect the starting of synchro motor. The damping t
28、akes off soldering and chooses silver actinium welding rod and adopts oxyacetylene welding to weld, the dynamo after taking out the core heats into rotor 200 Celsius degrees set rotor vertical in the oven, after taking out and adopt 750 Celsius degrees to or soly weld temperature, damping and the bl
29、ind side of of damping ring complete solderings are full, clear a soldering dirt again, ;For split of the damping , after dismantling original damping, choose the material of material homology and adopt the above-mentioned method to weld after packing good damping.Damping ring the wildfire is mainly
30、 what damping ring indirectly touches bad or get in touch with area isnt enough to result in. Damping ring the strain seriously is mainly a damping to fix anticoincidence in the slot, the damping plugs into damping ring while welding hole falsely, appear additional stress after welding, at plus damp
31、ing ring intensity not enough to, treatment is loose open all connectivity bolts of damping rings, vs strain anti big of damping ring, after oxyacetylene welding heating adjust with the exclusive use fixture even, vs strain serious replace a new damping of ring.2 - The solid instance is analyticalSo
32、lid instance 1 a synchro motor adopt nonsynchronous starting law, invest Li magnetoelectricity streaming post - but hard lead long into synchronization.Aim at the above-mentioned condition, halt after, check first whether power supply voltage is normal, then make use of multimeter and oscillograph v
33、s the Li magnetic belt device scrutiny, the Li magnetoelectricity presses, whether current is normal, end is doubt a short-circuit of the winding of Li magnetic belt to, .Press the preceding paragraphs the method for giving, can open into low - tension in the rotor derivation on - line(about 30 Vs)
34、,put on the magnetic poles surface with a hand work steel saw, pursue an inspection magnetic poles, discover the vibrating of saw blade micro or dont flap and explain the magnetic poles short circuit.After unloading the magnetic poles, use to shake a table inspection, recognize the magnetic poles wi
35、ndings short circuit.Is further to check, discover depend outside layer of the 2 F wire full circle insulated failure, put coil in the oven to heat into 150 Celsius degrees, make wire full circle the insulated anneals and lightly start to pry short-circuit section actinium row, use after the 0.03 mm
36、s the ring oxidizing glass cloth board packing sheet to go into, again brush 1 F 1032 paint after, put at the oven near roast dry, finally brush the 1 F 183# insulated lacquer, install magnetic poles.The dynamo after assembling the starting leads long into synchronization smoothly.Solid instance 2 s
37、ome plant when a synchro motor start choked to death because of the machinery, start the super - in time to grow, dont park the car in time, again starting, the damping ring discharges.Aim at the above-mentioned condition, open a dynamo port box, check damping ring to become a S shape, damping and d
38、amping ring having take off soldering.The reason is analytical:The dynamo divides six most solid magnetic poleses and starts because of the multifarious heavy load and once appeared damping to take off soldering and split before, the damping ring transforms serious fault, adopted to repair soldering
39、, damping replaced to split, replaced measures like damping ring,etc.If this adopts same transaction measure, the fault cans not get thoroughly removal. In consideration of the dampings ring is whole type structure, the big current expanded severity because of heat rum while flowing, but solid magne
40、tic poles again start only surface of magnetic belt Xue have fever and expand smaller, with of damping ring because of expand the degree is different, spark two of displacement with opposite creation and thermal stress, cause damping ring serious and take off faults like soldering,etc, .For overcomi
41、ng this kind of bug, this carries on a remould to the dampings ring and cut into damping ring all 6-like in shape rings, in each ring both ends drilling one more a link a composition segment type damping ring, can wipe - out the internal stress and thermal stress that whole damping ring generates li
42、ke this.3 ConclusionWhen the synchro motor appears fault, cautiously analytical possible reason, gradually expel, look into related data when its necessary, absorb experience, propose corrective actions.Analytical the dynamo fault not only need to have firm theory knowledge and experience of prolifi
43、c maintenance repairs, but also need to aim at concrete fault, deep consideration, brave creative, the dynamo after ensuring to break down removal can stabilize run - time over a long period of time. 永磁同步电动机直接转矩控制系统0 - 引言同步电动机由于具有功率因数高,运行效率高,稳定性好,转速恒定等优点,被广泛应用于工业生产中。熟悉同步电动机的起动故障,并及时排除故障,对电动机本身及生产系统都
44、有重要的意义。为了能及时、准确的排除故障和处理故障,必须对同步电动机的常见故障进行详细分析!1 - 常见故障1.1-同步电动机通电后不能起动同步电动机起动后不能运行一般有以下几个方面的原因:(1)电源电压过低。由于同步电动机的起动转矩正比于电压的平方,电源的电压过低使同步电动机的起动转矩大幅下降,低于负载转矩,从而无法起动,对此要提高电源电压,以增大电机的起动转矩。(2)电动机本身的故障。检查电动机定、转子绕组有无短路、断路,开焊和连接不良等故障,这些故障都会使电机无法建立起起动的额定的磁场强度,从而使电机无法起动;检查电动机轴承有无损坏,端盖有无松动,若轴承损坏端盖松动,造成轴承下沉,与定子
45、铁心相摩擦,从而造成电机无法起动,对定转子故障可以用低压摇表,逐点查找故障情况,采取相应的处理方法;对轴承和端盖松动的情况,每次开车前都要盘车,看电动机转子转动是否灵活,如果轴承或轴瓦损坏,要及时更换。(3)控制装置故障。此类故障多为励磁绕组的直流输出电压调整不当或无输出,造成电动机的定子电流过大,致使电动机过电流动作或电机的失磁运行。此时应检查励磁装置的输出电压电流及其波形是否正常,熔断器是否熔断,接触不良;电路板插件是否插牢或对准;检查回路电阻,灭磁铁晶闸管是否烧断或击穿。(4)机械故障。如被拖动的机械卡住,造成电动机不能起动,此时应盘动电动机的转子看转动是否灵活,机械负载是否存在故障。1
46、.2-同步电动机不能牵入同步。 同步电动机常用的异步起动法,在电动机转子转速达到95%同步转速时投放励磁,使之牵入同步。同步电动机不能牵入同步的原因如下:(1)励磁绕组短路。由于励磁绕组、存在短路故障,因而不可能产生额定磁场强度,导致电动机只能在低于同步转速下稳定运行而不能牵入同步。查找励磁绕组短路,可在转子引出线上通入低电压(约30V),用一根手工钢锯条放在磁极面上,逐个检查磁极,如果该磁极面上钢锯条振动剧烈,说明该磁极没有短路,如果锯条微振动或不振,说明该磁极短路。卸下该磁极后,检查该故障点,是短路程度,采取局部修理或重新绕制。(2)电源电压过低。电源电压过低,造成励磁装置的强励环节不能动
47、作,从而使电动机不能牵入同步,具体办法是适当提高电源电压。(3)励磁装置的故障。如投励过早(即投入励磁时,电动机转子转速过低),会使电动机无法牵入同步,此时应检查投励环节是否存在故障。如励磁装置故障,输出的电流低于额定值,导致电机的电磁转矩过小而无法牵入同步,此时应仔细检查励磁装置的投励环节和移相环节,用示波器检查投励环节和移相环节的波形,还应检查灭磁环节灭磁晶闸管是否正常发现问题,及时处理,如不能及时处理,为了能快速恢复生产,应更换备用电路板。1.3-电刷及压紧弹簧、集电环故障。电刷过短,压紧弹簧压力不足,使得电刷和集电环之间接触不良,从而产生火花或电弧,电弧或火花一方面易引起短路,另一方面
48、会使电弧烧得更短,从而引起断路,造成励磁装置只有励磁电压而无励磁电流;压紧弹簧老化失效,使得电刷和集电环之间接触不良,从而影响电动机的起动;集电环表面有油垢、条痕或沟痕,会使电刷和集电环之间接触不良,产生火花,火花进一步灼伤集电环,也会造成接地短路,火花从而影响电动机的起动。对于集电环表面的油垢,可以用丙酮擦洗干净;对于细条痕迹,用砂纸多次打磨环面,是环面粗糙度达到R1.6um,如沟痕明显需上车床加工,车削时,进刀量以每次1mm为宜,车削速度控制在1-1.5m/s,粗糙度达到R1.5-1.8um之间,变差不超过0.05mm,最后用砂纸抛光2-3次。1.4-阻尼绕组故障。同步电动机转子的阻尼绕组供同步电动机起动用,同时消除运行中由于负载变化而引起的失步振荡。在同步电动机起动过程中阻尼绕组切割定子旋转磁场而感应出很大的起动电流,这样大的电流必然会造成阻尼条发热膨胀,正常情况下由于起动时间短,阻尼绕组起动后很快就会冷却,但在电动机堵转,缺相,起动时间过长等情况下,若不及时停机,将会造成阻尼条脱焊断裂等情况。阻尼绕组是同步电动机部件中较为薄弱的环节,阻尼绕组常见的故障有:阻尼条脱焊、断裂,阻尼环间放电大火,阻尼环变形严重。这些故障都会影响同步电动机的起动。阻尼条脱焊,选用银铜焊条,采用气焊焊接,电机抽心后,将转子在烘箱内加热至200摄氏度,取出后,将转子垂直放置,采用750摄氏