直流调速系统毕业设计中英文对照翻译26页

1、河南理工大学毕业设计说明书DC governor system outlinedDC governor is artificially or automatically change the direct current generator rotational speed to meet the For mechanical requirements. From the mechanical properties point of view, is that by changing the parameters or electric motors plus The voltage elec

2、tric motors and other methods to change the mechanical properties, thus changing electric motors and mechanical properties Mechanical properties of the claimed identity work for the stability of operation of electric motors changed. There will be a link to the governor, usually through the middle en

3、larged link, calibration links, feedback links and other links to achieve protection. The rotational speed electric motors not given rotational speed automatic calibration and error system as a part of the governor control system. This governor system of rotational speed electric motors and power su

4、pply voltage fluctuations to be load fluctuations, the impact of external disturbances. Electric motors to the rotational speed automatic calibration and given rotational speed deviations from load voltage and power fluctuations, the impact of external disturbances to the rotational speed electric m

5、otors always consistent with the rotational speed of the governor to be known as loop system control system. This is due to a feedback loop control system link. Electrical transmission control systems usually by electric motors and control devices and information devices three parts. It can comply w

6、ith the requirements of orders, the timely control of electric motors starting, braking, direction of the operation, location, speed and acceleration, work machinery and production processes to meet the requirements. With electrical, sensors, control devices, the flow of technology and change contro

7、l theory, electrical transmission control systems have been greatly developed. Currently, the single aircraft used electrical capacity from a few hundred kilowatts to tens of thousands of kilowatts, and change the flow of equipment from the rotary kiln electrical flow change Jingzhaguan stationary p

8、ower units to change flow devices, and power off devices from static frequency conversion devices; Control module from the simulation of sensors, conditioners, will be integral to the development of devices to microprocessors chips at the core pay, DC generic digital volume control module; system co

9、ntrol mode switching from manual operation of multi-parameter control to servo control; from simple mechanics to electrical transmission system expansion for location, speed, acceleration control of the important branches of the movement control. In short, modern electrical transmission control syst

10、em has been developed into a new electrical transmission automation system.DC governor advantage Direct current generator is a good, braking performance, appropriate in a broader context, smooth mechanics, rolling mill, mine hoist, excavator, marine rigs, metal cutting machine tools, paper planes, s

11、uch as the need for high-performance high-lift electricity fees Controllable areas received widespread application. In recent years, exchanges governor system developed rapidly, but direct current fees system in theory and practice are relatively mature, and from the feedback loop control perspectiv

12、e, it is the exchange control system based fees, so direct current governor system in the production and living and play a vital role. DC governor system, in particular the double-loop DC governor system is the most widely used industrial production process electrical transmission devices one. Widel

13、y used in steel rolling machines, metallurgy, printing, metal cutting machine tools, and many other areas of automatic control system. It is usually used three-phase full control of the bridge commutation circuits for power electric motors to control the rotational speed of electric motors, the trad

14、itional control systems using analog components, such as transistors, various linear circuit operation, although to some extent to meet production requirements, but because of aging components and easy to use, are vulnerable in the outside interference effects, and complex circuits, overall poor con

15、trol results by device performance, temperature and other factors, thereby causing the operation of the system characteristics also change accordingly, the operating system reliability and accuracy can not be guaranteed, even in accidents.Double-loop system integral DC governor Rotational speed, the

16、 current two-loop systems theory governor figure 2-1. By the plan shows that the system has two feedback circuit, a 2 loop circuit (so called double-loop). One is the current regulator Lt and current testing - the current part of a feedback link, and another by the speed regulator St rotational spee

17、d detection-a feedback link speed link. As part of the Central buildings currents, the currents that threatened to Central (boys Deputy Central), said speed link to cry (that the main part). In the circuit, a string St and Lt level connectivity from St to drive Lt, and then from Lt to the control tr

18、igger circuit. Chart speed regulator and current regulator are proportional plus integral (PI) regulator, the import and export of a limited Deputy currents are located. Rotational speed link called current rapid change in response to rotational speed, and currents are required to maintain current C

19、entral unchanged. This performance will be detrimental to current changes in response to rotational speed, the better to calm character soften Momentum. But as part of a dedicated rotational speed, current role only a part of a rotational speed of internal disturbances. Central, not the leading role

20、. As a part of the rotational speed link enlarged multiple large enough, the last still relying on the scoring St. Eliminate rotational speed deviations. Double-loop mechanical governor system features As for St Pi regulator, the system was not very bad, repeatable error small, the general said, mos

21、tly To meet production requirements. Its mechanical properties similar to a horizontal line, as shown in figure 2-2a. When electric motors serious overload, and when II, the current regulator would export fairing Voltage significantly reduced, which limits the current continued to grow, on the other

22、 hand will rotational speed rapidly in a very steep the droop characteristics figure 2-2b.DC mechanics of the digital system With microelectronic technology, microprocessors and computer software development for the control of the governor through a variety of functions in almost all microprocessors

23、, the use of software to achieve. From the past to control the simulation modelling - controlled digital mixed development, the final realization of the entire digital. In digital systems, with the exception of the governor of conventional functions, but also a failure warning, diagnosis and shows,

24、and other functions, and digital systems usually have strong communication capabilities, through matching appropriate communications interface templates can easily achieve the main station (as mentioned level Plc or computer system) and from stations (single handed, DC transmission control devices),

25、 the number of digital communications, multi-aircraft formation automated classification system. For easy debugging, digital systems software, the general design of a regulator parameters optimized automation, optimization through a process to achieve an excellent and the automatic identification sy

26、stem dynamics parameters, and the achievement of identity, such as direct current generator magnetization curve automatic test helps to shorten the debugging time and improve control performance. Some foreign companies have a range of electrical adjustment system with simulation corresponds to the a

27、ll-digital, DC mechanics device products for the selection and development of new governor almost entirely digital system. And simulation systems similar, all-digital system developed for the compact style and mechanics of modular two broad categories. However, all-digital simulation of a governor o

28、r governor system incomparable advantages of the system, more advanced technology, easy to operate. Governor system and the digital system simulation governor compared technical performance following advantages : 1) high-precision attitude toward long-term maintenance. 2) good dynamic performance, d

29、ynamic parameters for the adjustment, given the rich software to achieve various adaptive and composite control. 3) governor a wide 4) Small voltage fluctuations 5) parameters of the software, no drift impact 6) the number of components used less difficult lapse 7) a high degree of value to quantify

30、, and repeat rate good condition 8) coupled noise amplifier and a small class, small electromagnetic interference 9) the operation of flexible debugging convenient and easy to design and modify the design 10) the high degree of common standards and, in addition to the CPU module, only several additi

31、onal modules Achievable, including parameters, multiple loop control techniques 11) scope of application can be achieved easily achieved with various gear shift control and communications systems Plc 12) conventional Jingzhaguan DC mechanics available software system to replace a large number of har

32、dware, thus simplifying system architecture and reducing the electronic components Xuhan, access to undesirable substances such as lead and some failures, and maintenance convenienceDC governor system and the current development Nearly 30 years ago, for the following reasons, and promoted the rapid

33、development of power control systems exposed, one is to control the development of theory, a best control, the smart control self control, intelligence control. Corresponding control system is also exposed the practice gradually taking shape. The second is the development of electronic devices, cont

34、rol systems composition fees brought significant changes. Changes in the past used rotary flow units (electric motors to exchange direct current generator) for the smooth direct current generator mechanics, and the DC motors used to exciter also enlarged the magnetic power, magnetron control; By the

35、 1960s, there have been Jingzhaguan the fairing, not only economically, and improved reliability, and also showed a great deal of technical superiority. Integrated operations, and many other electronic amplifier modules have been promoted control structure changes. Third, the 1980s computer technolo

36、gy and communications technology development, and created a new dynamic control system consists age eight Chanpianji -32 spaces and the application of control systems have appeared, making it simpler structure, function stronger, higher reliability. With the development of computer technology, both

37、production and living among people of digital information increasing dependence. If the computer is the brain, the network is nervous, then the electrical drivetrain system is the skeleton and muscles. Between them is the perfect combination of modern industrial development. For DC governor system c

38、losely integrated with information systems, but also to improve its own performance DC governor system, the need for direct current governor of the entire digital control system. Shanpianji in DC has been widely governor system applications. For example, by Intel Corporation in 1983 to develop produ

39、ction MCS-96 series is currently one of the series of performance higher Shanpianji apply to high-speed, high-precision industrial control. Its high-grade type : 8 x 196KB, 8 x 196KC, 8 x 196MC, in a part of the exchange governor system applications more. The continuous development of direct current

40、 machine control theory, control strategy and control algorithms also increasingly complex. Expand Cullman recovery, etc., state observation devices, adaptive control, artificial neural networks, etc. are applied to a variety of direct current machine or direct torque control, vector control. Theref

41、ore, the DSP chip in the high-performance digital communication systems governor found themselves in the display arena. MCS320F240 companies such as TI DSP chip, with its higher performance as a system-wide digital DC mechanics preferred. TI recently introduced MCS320F240X series products companies

42、will lower prices to Danpianji level. In direct current governor of the entire digital process, the various bus also plays a very important role. STD bus, industrial PC bus, the bus and the can bus, in exchange automation applications governor system has played an important role. Although DC mechani

43、cs developed very quickly, but the whole digital DC reversible system will in the next governor will get a large number of application equipment.Outlook From the traditional system, although in recent years the rapid exchange of electrical mechanics technology development in many areas is direct cur

44、rent machine mechanics technology expansion in DC mechanics research and manufacturing process, the design and assembly of hardware accounted for a large proportion. Manufacture and the manufacture of electrical devices require a large number of mechanics and skilled workers, a certain quality of pe

45、rsonnel requirements. Foreign related industries relatively high labour costs in the last decade, manufacturing DC governor may transfer to developing countries. In the case of China, this is also an opportunity, if we seize this opportunity, take advantage of their favorable market conditions, it i

46、s possible to form a direct current governor system in our manufacturing center for Chinas industry to a new level. It must be developed in high-tech areas will not easily give up, they paid great attention to the core technology and software protection and security and, to that end, we must increas

47、e research and development in the field of intensity. Switch toIntroduction to DC MachinesDC machines are characterized by their vcrsatilityBy means of various combinanons of shunt，serie5,and separately excited field windings they can be designed to display a wide variety of voltampcre or speedtorqu

48、e characlersics for both dynamic and stcadystate operationBecause of the ease with which they can be contro11ed，systems of DC machines are often used in applications requiring a wide range of motor speeds or precise contro of motor output. The essential features of a DC machine are shown schematical

49、lyThe stator hassalient poles and is excited by one of more field coilsThe air-gap flux distribution created by the field winding is symmetrical about the centerline ofthe field PolesThis axis called the field axis of direct axis As we know,the AC voltage generated in each rotating armtue coiI is co

50、nverled to DC in the external armature terminals by means of a rotating commutator and stationonary brushes to which the armature leads are connectedThe commutingorbrush combination forms a mechanical rectifier ，resulting in a DC armature voltage as wellas an armature mmf.wave which is fixed in spac

51、eThe brushes are located so that commutation occurs when the coil sides are in the neutral zone,midway between the field polesThe axis of the armature mmL wave then is 90 electrical degrees from the axis of the field poles，ie，in the quadrature axisIn lhe schematic representation the brushes are show

52、n in quadrature axis because this is the position of the coils to which they are connectedThe armature mmfwave then is along the brush axis as shown(The geomctricaI position of the brushes in an actual machine is approximately 90 electical degrees from their position in the schematic diagram because

53、 of the shape of the end conncdions to the commutator) The magnetic torque and the speed voltage appearing at the brushes are independent of the spatial waveform of the flux distributions; for convcenience we shall continue to assume a sinusoidal fluxdensity wave in the air gapThe torque can then be

54、 found from the magnetic field viewpoint. The torque can be expressed in terms 0f the interaction of the directaxis airgap flux per pole and the spacefundamental component of the armature mmfwaveWith the brushes in the quadrature axis the angle between these fields is 90 elcctrical de8rees，and its s

55、ine equals unityFor a Ppole machine：in which the minus sign gas been dropped because the positve difection of the torque can irection of the torque can bedetermined from Physical reasoningThe space fundamental of thc sawtooth armature mmfwavetimes its peakSubstitution in above equation then giveswhe

56、re =currcnt in external armature circuit； Catotal number of conductors in armature winding; mnumber of parallel paths through winding；and is a constant fixed by the design of the winding. The rectified voltage generated in the armatufe has already been disscussed before for an elementary singlecoil

57、armature. The effect of distributing the winding in several slots is shown in figure，in which each of the recufied sine waves is the voltage generrated in one of the coils，commutaion taking place at the moment when the coil sides are in the neutralzoneThe generated voltage as observed from the brush

58、es shown by the rippling line labeled in figureWith a dozen or so commutator segments per pole，The ripple becomes very small and the average generated voltage observed from the brushes equals the sum of the average values of the rectified coil voltagesThe rectified voltage ea between brushes，known a

59、lso as the speed voltage,iswhere Ka is the design constantThe rechfied voltage of a distributed winding has the same average value as that or a concentrated coilThe differcnce is that the ripple is greatly reduced. From the abovc equations，with a11 variable expressed in SI units：This equation simply sa