【机械类毕业论文中英文对照文献翻译】变频技术的普及前景
收藏
资源目录
压缩包内文档预览：(预览前20页/共22页)
编号：77688664
类型：共享资源
大小：31.78KB
格式：RAR
上传时间：2020-05-07
上传人：柒哥
认证信息
个人认证
杨**（实名认证）
湖南
IP属地：湖南
6
积分
- 关 键 词：
-
机械类毕业论文中英文对照文献翻译
机械类
毕业论文
中英文
对照
文献
翻译
变频
技术
普及
前景
- 资源描述：
-
【机械类毕业论文中英文对照文献翻译】变频技术的普及前景,机械类毕业论文中英文对照文献翻译,机械类,毕业论文,中英文,对照,文献,翻译,变频,技术,普及,前景
- 内容简介：
-
编号无锡太湖学院毕业设计（论文）相关资料题目：三菱变频器对异步电动机调速控制 三相异步电动机调速控制系统设计 信机 系 机械工程及自动化专业学 号： 0923135学生姓名： 周 磊 指导教师： 宋广雷（职称：副教授 ） （职称： ）2013年5月25日目 录一、毕业设计（论文）开题报告二、毕业设计（论文）外文资料翻译及原文三、学生“毕业论文（论文）计划、进度、检查及落实表”四、实习鉴定表无锡太湖学院毕业设计（论文）开题报告题目：三菱变频器对异步电动机调速控制 三相异步电动机调速控制系统设计 信机 系 机械工程及自动化 专业学 号： 0923135 学生姓名： 周 磊 指导教师： 宋广雷 （职称：副教授 ） （职称： ）2012年11月25日课题来源自拟题目科学依据（包括课题的科学意义；国内外研究概况、水平和发展趋势；应用前景等）（1）课题科学意义电动机作为把电能转换为机械能的主要设备，在实际应用中，一是要使电动机具有较高的机电能量转换效率；二是根据生产机械的工艺要求控制和调节电动机的旋转速度。电动机的调速性能的好坏对提高产品质量，提高劳动生产率和节省电能有着直接的决定性影响。众所周知，直流电动机的转速容易控制和调节，采用转速电流双闭环直流调速系统可获得优良的静动态调速特性。因此长期以来，在变速传动领域中，直流调速一直占据主导地位。但是，由于直流电动机的机械式换向器和电刷存在着诸多弱点，因此有时直流调速也受到限制。然而，采用无换向器的交流电动机组成的交流调速系统代替直流调速系统可以突破这些限制，满足生产发展对调速、传动的各种不同的要求。交流电机调速技术的发展，特别是变频器传动本身固有的优势，必将使之应用于社会生产的各个领域，以体现出不同的功能，达到不同的目的，收到相应的效益。因此，本论文通过对变频器的研究，对于交流变频调速系统理论的应用，有着实际的意义和一定的应用价值。（2）三相异步电动机变频调速系统的研究现状及其发展前景随着变频技术的不断的发展，通用变频器以其优异的控制性能现已在调速领域、工业领域及家电产品中得到迅速推广。此外，变频技术和变频器制造己经从传统的拖动技术中分离出来，现已成为各国在工业自动化和机电一体化领域中争强占先的阵地，而发达国家更是在该技术领域投入了极大的人力、物力、财力，逐步向高新技术行业发展。（1）网络智能化智能化的变频器可以进行故障自诊断、遥控诊断以及部件自动置换，从而保证变频器的长寿命。利用互联网可以实现多台变频器联动等综合管理控制系统。（2）专业化和一体化变频器的制造专业化，可以使变频器在某一领域的性能更强，如风机、水泵、电梯、起重机械和张力控制专用变频器等。此外变频器与电动机一体化的发展趋势，使变频器成为电动机的一部分，逐渐向体积小、易控制的方向发展。（3）适应新能源以太阳能和风力为能源的燃料电池以其低廉的性能已得到广泛的应用。这些发电设备的最大特点是容量小而分散，将来的变频器就要适应这样的新能源，既要高效，又要低耗。随着电力电子技术、微电子技术和现代控制技术的快速发展，变频调速传动技术也随之取得了日新月异的进。主要表现在交流调速装置的大容量化、变频器的高性能化和多功能化、结构的小型化等方面。研究内容 熟练地掌握电动机的原理和控制的方法 熟练掌握三菱变频器的安装及其原理 熟练掌握三菱变频器对异步电动机的调速 掌握电动机与变频器之间的连接和注意事项 能够熟练掌握CAD对电路图等等的绘制 拟采取的研究方法、技术路线、实验方案及可行性分析研究方法：通过参阅借来的参考资料，并对三相异步电动机和三菱变频器进行实体的观察，认真的研究，了解他们的基本内容，与指导老师一起合作完成毕业设计。技术线路：提出任务分析对系统的需求确定任务要求，完成任务书。方案的设计阶段对三相异步电动机进行分析和提问，并提出一些解决的方案。组合几种方案进行整理。选定最好的方案进行实操，并对一系列的数据进行整理。合理的试用一些参考文献和说明书。技术可行性：作为研究内容所需要的软件CAD，研究计划及预期成果研究计划：2012年11月12日-2013年1月20日：按照任务书要求查阅论文相关参考资料，填写业设计开题报告书。 ， 2013年2月11日-2013年2月235日：找一篇相关的外文期刊并翻译。构建框架，完成第一章绪论。2013年3月4日-2013年3月8日：完成总的结构方案设计。2013年3月11日-2013年4月20日：开始着手设计系统。2013年4月22日-2013年5月3日：着手写说明书初稿，修改，完成初稿。2013年4月22日-2013年5月10日：修改说明书并打印，整理资料主被答辩。预期成果：对三相异步电动机的变频调速有了逐步的了解，并且可以很好地完成系统的设计。特色或创新之处主题明确，有针对性，稳定，易操作，通用性强。 使用简易，功能完善。已具备的条件和尚需解决的问题 技术条件：整体的构架基本明确，有很好的参考资料。尚未解决的问题：技术还不够成熟。指导教师意见 指导教师签名：年 月 日教研室（学科组、研究所）意见 教研室主任签名： 年 月 日系意见 主管领导签名： 年 月 日英文原文1 Frequency Variation Speed Control1.1 The Popularity and Prospect of Frequency Variation Speed ControlThe electrical machinery exchange frequency conversion velocity modulation technology is the electricity saving, the improvement technical process improves the product quality and the improvement environment, the impetus technology advancement one main method now The frequency conversion velocity modulation by its outstanding velocity modulation and the braking quality, the high efficiency, the high power factor and the electricity saving effect, the widespread applicable scope and other many merits by the domestic grandfather was thought most has the development future velocity modulation way. The electrical transmission control system usually by the electric motor, the control device and the information installs 3 parts to be composed, the electrical transmission relates uses the electric motor by to save the electrical energy and to control the machinery reasonably the operating condition, the realization electrical energy - mechanical energy transformation, achieves, the high production, the low consumption goal high quality. The electrical transmission divides into does not modulate velocity and modulates velocity two big kinds, the velocity modulation is divided the exchange to modulate velocity and to direct current modulates velocity two ways. The variable speed motor directly does not supply power by the electrical network But the machinery which does not modulate velocity along with electric power electronic technology development this kind of original manuscript more and more many changes to the velocity modulation transmission by to save the electrical energy The improvement product quality, enhances the output Therefore the velocity modulation transmission is an important profession, already obtained the country to take, at present had certain scale.In recent years exchanged in the velocity modulation most to be active, to develop quickest is the frequency conversion velocity modulation technology, the frequency conversion velocity modulation is exchanges the velocity modulation foundation and the branch content. The last century transformer appearance causes the change voltage to become very much easy, thus has accomplished a huge electric power profession. Since long ago, the alternating current frequency always is fixed, the frequency conversion velocity modulation technology appearance causes the frequency to become may the full use resources.In this recent 10 years, the frequency conversion technology application has the very big development in our country, and obtained the good effect to be possible to say, the frequency conversion technology has accepted for the majority users, but had no alternative but to point out, our country in frequency conversion technology application aspect, with developed country level Shang You very big disparity. At present, the AC motors we are using now use frequency variation speed control only about 6%, but the developed country is 60%70%, Japan on air blower, water pump frequency conversion velocity modulation use rate is 10%, but our country is less than 0.01%, In Japan air-conditioner using frequency variation technique rate is 70%, but our countrys only then just started Embarks from this reality, frequency conversion technology remain have the very big development space, we should complete the promoted application work doggedly.And with the constant development of control technique and control avenue, frequency variation speed controlled has developed the vector controlled frequency variation velocity modulation, by controlling the AC motor inside act for shunt DC motor field copers flux, to enhance the permanent torque output scope and static and dynamic character, make the AC motor frequency variation speed controlled system superior to DC motor voltage variation speed controlled system. For simplifying the control system, reducing the fault rate, there has developed a vector controlled frequency variation speed control without speed sensor which based on the vector controlled frequency variation speed control. In some application which have low require , vector controlled frequency variation speed control without speed sensor could completely compare with the vector controlled frequency variation speed control that have speed sensor. The vector control has the epoch-making significance to the AC current motor velocity modulation.Frequency variation speed control is the best way in the motor speed modulation, it is the perfect gear in the companys technical reform and product renewal, it is the essential composition in the industrial automatic system, it is the assumption of realizing the automatic of product proceed and management, it is also the precondition in the development of informationization. In our countrys traditional estate, using the DC motor speed control actuation account about 85%90% in the speed controlled system, but the AC speed controlled system account about 10%15%. Low efficiency, bad quality, large cost, high fault rate have already been the bottleneck that restrain the development of the company. So, we must promote the advanced AC frequency variation speed control technique positively, arms the traditional industry with the advanced equipment, promote a further development in the automation, the industrialization and the informationization.1.2 Our Countrys Development Condition in Speed Controlled TechniqueOur country is a developing country, so many products research ability has behind the developed countries. From now on, the product of frequency variation speed controlled that ourselves made only act for last century 90s in the international. With the reform and opening, rapid development of economic, forms a large market, it opens to the country companies, also the foreign companies. Many products are exported from the developed countries, and runs well in our country, satisfied our need in fabrication and living. Many co-partership companies in our country make the international advanced products. The domestic complete department independently is designing the manufacture in the complete set installment to use the foreign import company and the joint venture supposes advanced each, own develop the application software, can provide the first-class electrical transmission control system for the domestic and foreign important engineering project. Although obtains very many result, but should see because domestic develops, the production product ability voluntarily is weak, is serious to the overseas companys dependence.As early as in the country 85 technical attack plan, the alternating velocity modulation technique was listed as the key technical attack project, but because our countrys electric power and electronic device aggregate level is very low, although the production of IGBT、GTO component has introduced the overseas technique, it has not formed the economies of scale benefit, almost does not have the independent development ability of new frequency converter production, this has affected the domestic frequency conversion velocity modulation technique development in the certain degree. In the high efficiency AC-AC frequency convert technique、the motors without commutator technique and so on, the domestic product also has the suitable disparity in the digitization and the system reliable aspect compares with the overseas level, in the medium efficiency frequency convert technique, nearly all productions use ordinary V/F control inland, few adopt the vector control technique, and can not satisfied the market requirement in the variety and quality. But in overseas, the frequency conversion technique obtains the full development, and has obtained the remarkable achievement in each aspect. In power component aspect, high voltage、the appearance of SCR、GTO、IGBT、IGCT with high current capacity and the using in series and parallel, the high-pressured and high efficiency frequency converter production obtains the production and the promoted application. In microelectronic technique aspect, 16bit and 32bit high speed microprocessors as well as the fast development of DSP and ASIC technique, provided the hardware method in realizing the frequency converter which with high accuracy multi-purpose. In theory aspect, the vector control, the magnetic flux control, the torque control, the intelligent control, the new control theory and so on have provided the related rationale for the high performance frequency converter development, we may see that, in the overall, the alternating frequency conversion velocity modulation technique in our country has big disparity compares with international level.Therefore, the AC frequency variation speed control technique has the following sides:1) The basic research of control strategy in frequency converter has a large gap compares with the foreign level.2) The technical level of the whole machine is low in the frequency converter, although we had input certainly people, material resources, but because of the disperse power, did not form a certainly technique and production scale.3) All the semiconductor power device product in the frequency converter is blank.4) Correlative Industries and relative Industries drop behind.5) Few production and sale, low reliable and technological standards.With the development and improvement in the power electronic technique, power divert based on power electronic circuit technique and various control technique, the AC frequency variation speed controlled technique is mature day by day, and sure to be the main way in the future. With the constant development of power electronic technique, reliable character, well adoption, cheap price that the frequency converter have will become true. This technique will gain widely, popularity application .At present, foreign developed countries frequency convert technique towards to the miniaturization, high reliability, defend with harm, more function, high character, and our country is coming on now.1.3 Frequency Variation Speed Controlled ModeThe alternating frequency conversion velocity modulation technique obtained the rapid development in 20th century. This is related with some crucial technical which gain unprecedented progress, they are Motor vector control technique, Direct torque control technique, PWM technique, Entire numerical control technique and self-setting technique which based on microcomputer and large scale integrated circuit, and so on.1) Vector Control TechniqueVector transformation control technique is a one kind of new control thought and control theory which posed by SIEMENS CO. in 1971. It is realizing the stator current excitation component and the torque component solution lotus root by rotor magnetic field direction detection, and vector transformation, achieved the goal that separately control the motor flux linkage and the electric current, as a result, obtain finely static, dynamic performance. Until now, the vector control technique has obtained the considerable development, and also obtained the widespread application.2) Vector Control Without Velocity Generator TechniqueVector control without velocity generator technique abolish the problems that the environment compatibility、install and maintenance bring on, reduce the cost, enhance the system reliability, at the same time, union vector control, has the fine performance of vector control. The speed estimate method in vector control technique without velocity generator, besides basis mathematical model computation electric motor rotational speed, at present the more applied are the model to refer auto-adapted method and expands the Kalman filtering law. In addition, entire Uygur rotor magnetic flux sight, tooth overtone electric potential, such as this theory and so on, also appearance in the vector control without velocity generator technique. Since 1983 proposed the vector control without velocity generator technique control strategy, receives the academic circles and the industrial field continuously highly focused all the time. Hitachi company and Sichuan electrical machinery and so on had published the research results separately in 1987, and had promoted the product one after another. At present, vector control without velocity generator technique in frequency converter controlling in the velocity modulation scope is about 1:50, some individual merchant has 1:75 or even higher product.3) Direct Torque Control TechniqueIn1985, Germanys M. Depen-block proposes the direct torque control technique（DTC） for the first time，The direct torque control technique analyzes the motor mathematical model directly under the stator coordinate system. Uses the stator magnetic field direction detection but not to need the solution lotus root electric current，directly control the electric motor flux linkage and torque, enable the torque to obtain the fast response, in order to obtain the highly effective control performance.Direct torque control technique is another kind of new、high performance alternating frequency conversion velocity modulation technique after vector control technique in the nearly 10 years, this kind of control technique is insensitive to the electrical machinery parameter, not influence by the rotor parameter, easy and feasible, it has the broad development and the application prospect.4) PWM (pulse width modulation) Control TechniqueIn1964, Germanys A. Schonung and some people took the lead to propose the pulse-duration modulation (PWM -pulse width modulation) frequency conversion thought, opened the recent development domain for the modern alternating velocity modulation system. The PWM control technique controls the inversion output alternating fundamental wave voltage peak-to-peak value by changing the rectangle pulse width, controls its output frequency through changing the modulation cycle, in order to carry on the output voltage peak-to-peak value and the frequency control on the inversion at the same time. The PWM technique simplified the inversion structure, can distinctly change the output wave shape of the frequency converter, reduces the overtone loss of electric motor, and reduces the torque pulsation, at the same time enhances the performance of dynamic response system. The PWM technique also may use in the rectifier controlling, can realize the input current which approaches the sine extremely. And may cause the electrical network power factor is 1. The PWM rectifier thus is called “the green converter”. At present, PWM technique has become the most widespread control technique applied in the frequency converter. The unceasingly velocity modulation performance of alternating current motor is as a result of the PWM technique unceasing progress enhancement in the very great degree. At present the widely applies is the optimizes PWM law which developing based on the regular sampling PWM foundation, that is Thrice Harmonic Superpose theory and voltage space vector PWM theory.5) Numerical Control TechniqueThe digitalize in control technique is the key technique of static frequency conversion installment, also will be the next development tendency, at present in the market frequency conversion installment nearly comprehensively has realized the numerical control. Has realized the fast operation and the high accuracy control by using the DSP and the ASIC technique, and could gain a fine current wave, reduce the noise of the frequency converter in a large scale, and the scanning time also be reduced in a large scale, at present the electric current response is 0.10.7ms, the speed response is 24 ms, could satisfy the control request sufficiently in the transmission domain. At the same time, on account of the application of the micro electron and ASIC technique, the installment primary device quantity can be reduced in a large scale, thus, could make the frequency conversion equipment volume to be reduced, the reliability obtains the large scale enhancement. The entire numerical control way can make the information-handling capacity of frequency converter enhance greatly. The complex control has been realized in nowadays which could not be realized by simulation control mode, so that, the RAS which mean Reliability, Availability, Serviceability could be realized.6) Self-setting TechniqueThe self-setting technique is widespread used in the frequency conversion velocity modulation system day by day, it may accord to the speed and the load to auto adjust the parameter of the control system, enable the system with rapid dynamic response. The self-setting technique divides into off-line and the on-line. The research results in the kind of off-line has been applied in the most production, before the system program operate, it operate a block self-setting program, recognize the correlation data, and amend the parameter of the system program that related, in order to gain a approved system control performance. Moreover, improve the control technique, enhance the robustness of the system, also have close relatives with self-setting technique.2 PLC interference analysis With the development of science and technology, the application in industrial control of PLC is more and more extensive. The dependability of PLC control system influences the safety in production and economical operation of the industrial enterprise directly; systematic anti-interference ability is the key to concerning the whole system and running reliably. All kinds of PLC used in the automated system, some install concentrated in the control room , some install in production scene and every electrical machinery equipment, they in strong electric circuit and strong electric abominable electromagnetic environment that equipment form mostly. Should improve PLC dependability of control systems, on one hand require PLC manufacturer to improve the anti-interference ability of the equipment; On the other hand, require engineering design, installation construct and use of maintaining causing paying close attention to, cooperate and perfect the problem of solving in many ways, strengthen systematic anti-interference performance effectively.2.1 Sources of interference and interference with the general classification It is like generally influencing the interference source of the industrial control equipment to influence the interference source of PLC control system, mostly producing the position in the electric current or violent change of voltage, these violent position that move of electric charge is the noise source, namely interfere the source.Interfere type interfere the division different from wave form nature of the noise of the mode according to reason, noise produced to interfere usually. Among them: According to reason that noise produce being different, is it discharge noise, wave well up noise, high frequency shake noise, etc. to divide into; Different according to the wave form, nature of the noise, divided into a lasting noise, accidental noiseless.; It is different to interfere the mode according to the noise, is divided into mould interfering and difference mould interference altogether. It is a kind of commonly more used categorized method that the mould interferes interfering with the difference mould altogether. It is signal electric potential difference to place for mould not to interfere altogether, bunch enter, ground electric potential difference and space electromagnetic radiation reaction attitude (with direction) voltage is it is it form to add to change altogether at signal line by electric wire netting mainly. Mould voltage sometimes relatively heavy altogether, is it isolate performance mixing electric apparatus supply power in the room bad to adopt, changer output voltage generally relatively high mould altogether of signal, some can up to 130V to be the above-mentioned. Mould voltage through asymmetric circuit getting convertible models voltage of difference, influence the signal of observing and controlling directly altogether, cause the components and parts to be damaged (this is some systematic I/O moulds a main reason of higher spoilage), this kind mould can interfere for direct current, can for exchange also altogether. The difference mould interferes referring to acting on the voltage of interference between the two poles of the signal, coupling reaction change voltage that moulds interfering form altogether by uneven circuit among signal by space electric magnetic field mainly, this kind superposes it on the signal directly, influence measurement and control the precision directly. 2.2 PLC control system electromagnetic interference the main source1) The radiation from space interference mainly produced by temporary attitude course , thunder and lightning , radio broadcasting , TV,radar, high-frequency reaction heating device of the electric network , electric equipment ,etc., usually called radiation to interfere, it is extremely complicated that it is distributed. Whether if PLC system put on radio frequency in the field is it reaches radiation interfere to retrieve, it influences and mainly passes two routes. First, produced and interferes by the reaction of the circuit to the radiation within PLC directly; But the radiation of the network, is introduced and interfered by the reaction of the communication line while communicating to PLC. Radiation is interfered with the on-the-spot equipment assigning and size of electric magnetic field that the equipment produce , especially frequency have something to do with, generally through set up shielding cable and PLC some shielding and high pressure discharge component protect.2) Interference from lead wire outside the systemIntroduce through the power and signal line mainly, is usually called and conducted interfering. This kind of interference is relatively serious at the industrial scene of our country.3) Interference from powerPractice has proved , interference introduced because of the power causes situations of PLC control system trouble a lot of, I meet in debugging in some project, is it isolate performance high PLC power to change, the problem is solved .Normal power supply power, PLC of system supply power by the electric wire netting. Because the electric wire netting is widely covered, it will be interfered the voltage of reaction and circuit on the circuit electromagnetically by all space. Change of electric wire netting, enter switch operate wave well up, large-scale electric equipment is it park, is it is it move in harmony wave, electric wire netting that device cause short out the attitude is bludgeoned into etc. temporarily to spread direct to pay to get up especially, it is through it is the original since transmission line of electricity last power. PLC power usually adopts and isolates the power, but its organization and manufacturing engineering factor make its isolating unsatisfactory. In fact, because of distributing the existence of the parameter especially distribution capacity, it is impossible to isolate definitely.4) Come from the interference that the signal thread introducesAll kinds of signal transmission lines connected with PLC control system, besides transmitting all kinds of effective information, always there will be outside interfering signals that will be invaded. This interference has two kinds of ways mainly: Supply power or share through changer power supply power a bunch of electric wire netting entered, signal of instrument interfere, this is often ignored; second, the signal line is influenced by space electromagnetic radiation reaction, namely the external inductive interference on the line of signal, this is very serious. Is it is it can cause I/O signal work by signal unusual measuring precision reduce greatly to interfere to introduce, will cause the components and parts to damage when being serious. For isolating the system with bad performance, will cause the mutual interference among the signals, cause the backset current of the systematic bus altogether, because logic data changing, work up by mistake and system halted. PLC control system cause by the fact that the signal introduces I/O mould piece is it count quite serious to damage, being caused situations of the systematic trouble by this is a lot of too.5) Interference while coming from the earth system confusedlyEarth to improve electronic equipment electromagnetic effective means of compatibility one of. Correct earth, can suppress the equipment to send out and interfere outwards not only can suppress the electromagnetic influence that interfere but also; And wrong earth, can introduce serious interfering signal instead , make PLC to be system unable to work normally .6) The ground wire including systematic ground , shielding , exchanging of PLC control system and protect the ground etc.Earth whether all connect the place electric potential misdistributions mainly to interference, PLC of system, different to connect person who have electric potential difference under place, person who cause cycle electric current, influence the system to work normally. For example cable shielding layer must one point ground, if cable shielding layer both ends A, B ground, person who store in electric potential difference, there is electric current that flows through the shielding layer, when the unusual state takes place and is struck by lightning, the ground wire electric current will be bigger.In addition, the shielding layer , earth connection and earth may be formed and closed the cycle, under changing the function of the magnetic field , will present the reaction electric current in the shielding layer, pass the coupling between the shielding layer and core line , the return circuit of interfering signal. If with deal with confusion by other earth systematically, ground circulation produced might is it vary the electric potential distribute to produce at ground wire, influence the normal work of the logical circuit and simulation circuit in PLC. Logic voltage that PLC work interfere tolerance to be relatively low, logic distribution of electric potential interfere apt to influence logic operation and datum of PLC store, lead to the fact the confusion of the data , procedure run and fly or system halted. Simulation distribution, ground of electric potential is it measure precision drop, it causes to be distorted and missing movements seriously to whom signal observe and control to result.中文译文1.1 变频技术的普及前景电机交流变频调速技术是当今节电、改善工艺流程以提高产品质量和改善环境、推动技术进步的一种主要手段。变频调速以其优异的调速和起制动性能，高效率、高功率因数和节电效果，广泛的适用范围及其它许多优点而被国内外公认为最有发展前途的调速方式。电气传动控制系统通常由电动机、控制装置和信息装置3部分组成，电气传动关系到合理地使用电动机以节约电能和控制机械的运转状态，实现电能-机械能的转换，达到优质、高产、低耗目的。电气传动分成不调速和调速两大类，调速又分交流调速和直流调速两种方式。不调速电动机直接由电网供电，但随着电力电子技术的发展这类原本不调速的机械越来越多地改用调速传动以节约电能(节约15%20%或更多)，改善产品质量，提高产量。在我国60%的发电量是通过电动机消耗的，因此调速传动是一个重要行业，已经得到国家重视，目前已有一定规模。近年来交流调速中最活跃、发展最快的就是变频调速技术，变频调速是交流调速的基础和主干内容。上个世纪变压器的出现使改变电压变得很容易，从而造就了一个庞大的电力行业。长期以来，交流电的频率一直是固定的，变频调速技术的出现使频率变为可以充分利用的资源。这10年来，变频技术的应用在我国有很大的发展，并取得了良好的效果可以说，变频技术已为大多数用户所接受，但是不能不指出，我国在变频技术的应用方面，与发达国家的水平尚有很大差距，目前，我国在用的交流电动机使用变频调速运行的仅6%左右，而下业发达国家已达(60%70%)，日本在风机、水泵上变频调速的采用率已达10% ,而我国还不足0.01%.在日本，空调器的70%采用了变频调速，而我国才刚刚起步。从这个现实出发，变频技术尚有很大的发展空间，应该锲而不舍地做好推广应用工作。而且随着控制技术和控制手段的不断提高，变频调速又由变压变频控制的变频调速发展到了矢量控制变频调速，通过控制交流电动机里相当于并励直流电动机励磁绕组的磁通变化，提高变频器的恒转矩输出范围和动静态特性，使得交流电动机变频调速系统的性能超过了直流电动机调压调速系统的性能。为了简化控制系统，减少设备故障率，在矢量控制变频调速的基础上又发展了无速度传感器的矢量控制变频调速。在一些对动静态特性要求不太高的应用中，无速度传感器的矢量控制变频调速己完全可以和有速度传感器的矢量控制变频调速相媲美。矢量控制对交流电机调速具有划时代的意义。变频调速是电机调速的最佳方式，是企业技术改造和产品更新换代的理想设备，是工业自动化系统必不可少的组成部分，是实现生产过程和管理自动化的前提，也是信息化发展的先决条件。在我国传统产业中，采用直流电机拖动的调速系统约占调速系统总量的85%90%，而交流调速系统仅占10%15%。效率低、质量差、消耗大、故障率高己成为制约企业发展的瓶颈。因此，必须积极推广先进的交流变频调速技术，用先进的设备武装传统产业，促进自动化、工业化和信息化的进一步发展。1.2 变频调速发展趋势如果说以第一个晶闸管的出现作为交流电动机变频调速的起点，可以认为它的发展历史己40多年了。而变频调速技术真正高速发展时期，应该是在PWM调制技术的出现和微机控制技术发展之后。特别是最近20年来，随着交流调速技术的应用普及，交流变频调速在化工、火电厂、矿山、油田、机械制造、城市建设、水处理、甚至家电等行业己经全面推广使用，一般主要用于节能及控制。随着变频技术的普及和深入，以及国际、国内电器设备使用的有关标准意识的强化，电力系统行业和用户对变频技术的质量要求也越来越高。变频调速的发展趋势主要围绕下面几个方而展开。1) 高性能的智能控制变频器380V系统的低压变频器是国内的主要研究对象，应用交流调速的基本理论，结合神经网络控制、鲁棒控制、模糊控制，或其他智能控制等手段，实现电机运行参数的自动辨识，以期达到自适应、自调整的最优控制。这方面己有一定的研究成果。2) 速度传感器研究从前面所述的各种变频调速的理论可知，一般系统都要用到转速传感器。在实际使用中，由于变频设备和被控电动机有一定的距离，而高精度的转速传感器都要使用专门的电源，被控电动机有的是在户外，运行工况非常恶劣，要保证速度反馈的准确性，有时不得不采取特别措施，因此也会增加额外费用，运行的可靠性和控制精度也会因此受到影响。无速度传感器的变频调速系统，是通过现场采集的电流电压量，以及控制的实施策略，综合出被控电机的实际转速。这种控制方案要求计算机的控制速度较高，并有足够的精度。3) 针对功率因数提高和谐波污染的研究低压变频调速系统的控制虽然己经是非常成熟了，但目前国际、国内的产品，一般都是矢量控制和直接转矩控制，重点放在电机变频控制理论的实现和完善上，而对变频器的输出波形、功率因数，以及谐波污染等问题还没有引起足够的重视。最近10多年来，国外在这一领域己有较深入的研究。有的针对功率因数，有的强调输出波形。多重化技术就是为了解决输出波形问题。最近几年的研究表明，利用PWM输出控制解决谐波输出问题，是比较理想的方法，它可以省去多重化中的变压器，或过多的开关元器件，使变频器的体积和重量减少，但这种方法不能解决所有谐波的消除问题，只能部分消除特定谐波。这方面的研究论文还不多，也还没有成熟的类似低压变频器的产品出现。4) 高压变频器的研究变频器的主要作用之一是节能。而高压电动机的节能效果是比较明显的，大功率的风机和水泵用电动机一般都是高压电动机。国内，高压变频调速和它的节能控制还是一个比较薄弱的环节.它主要是针对610kV的交流电动机进行变频调速控制。这种高压电动机广泛应用于火力发电厂的送风机和引风机上。同样也可用于其他如石油化工、矿山、冶炼、机械制造等行业的变频节能控制。从某种意义上讲，由于目前国内还不能完全生产高质量的合格电力电子器件，而且，国外低压变频器的性能价格比也比国内自己研究的变频器高得多。因此,在这方面还有许多研究工作要做。随着电力电子技术最近20多年的飞速发展，功率半导体器件的成本逐年下降，技术工艺和性能也得到不断改善.电力电子器件的应用己从传统的直流调速、直流屏、斩波器等领域延伸到交流调速和电力系统的质量控制领域.并正朝着高电压、大功率的方向发展.这也是千年之交和世纪之交我国电力电子技术应用的发展趋势。5) 无换向器同步电机的变频调速无换向器电动机也是在20世纪70年代发展起来的新型调速系统。它是一种变频调速同步电动机.也可以认为是一种用半导体电子开关线路代替换向器和电刷作用的直流电动机。根据采用的控制方式不同.可分为直流无换向器电动机和交流无换向器电动机。直流无换向器电动机采用交-直-交或直-交变频控制系统;交流无换向器电动机采用交-交变频控制系统。近10年来.国内外杂志上有许多相关的研究论文。而且，也有一定的成果出现。1.3 变频调速控制方式交流变频调速技术在20世纪得到了迅速发展。这与一些关键性技术的突破性进展有关，它们是交流电动机的矢量控制技术、直接转矩控制技术、PWM技术以及微型计算机和大规模集成电路为基础的全数字化控制技术、自整定技术等。1) 矢量控制技术矢量变换控制技术是西门子公司于1971年提出的一种新的控制思想和控制理论。它是以转子磁场定向，采用矢量变换的方法实现定子电流励磁分量和转矩分量之间的解藕，达到对交流电动机的磁链和电流分别控制的目的，从而获得了优良的静、动态性能。迄今为止，矢量控制技术己经获得了长足的发展，并得到了广泛应用。2) 无速度传感器矢量控制技术无速度传感器控制技术免去了传感器带来的环境适应性、安装维护等问题，降低了成本，提高了系统的可靠性，同时结合矢量控制，具有矢量控制的优良性能。无速度传感器技术中速度估算的方法，除了根据数学模型计算电动机转速外，目前应用较多的有模型参考自适应法和扩展卡尔曼滤波法。此外全维转子磁通观测器，齿谐波电势(RSH)等理论也出现在无速度传感器技术中。从1983年提出无速度传感器矢量控制策略以来，一
- 温馨提示:
1: 本站所有资源如无特殊说明，都需要本地电脑安装OFFICE2007和PDF阅读器。图纸软件为CAD,CAXA,PROE,UG,SolidWorks等.压缩文件请下载最新的WinRAR软件解压。
2: 本站的文档不包含任何第三方提供的附件图纸等，如果需要附件，请联系上传者。文件的所有权益归上传用户所有。
3.本站RAR压缩包中若带图纸，网页内容里面会有图纸预览，若没有图纸预览就没有图纸。
4. 未经权益所有人同意不得将文件中的内容挪作商业或盈利用途。
5. 人人文库网仅提供信息存储空间，仅对用户上传内容的表现方式做保护处理，对用户上传分享的文档内容本身不做任何修改或编辑，并不能对任何下载内容负责。
6. 下载文件中如有侵权或不适当内容，请与我们联系，我们立即纠正。
7. 本站不保证下载资源的准确性、安全性和完整性, 同时也不承担用户因使用这些下载资源对自己和他人造成任何形式的伤害或损失。
人人文库网所有资源均是用户自行上传分享，仅供网友学习交流，未经上传用户书面授权，请勿作他用。
川公网安备: 51019002004831号