通信与信息系统论文.doc

通信与信息系统论文以下资料为精心收集整理，免费提供给大家，建议可以先下载再阅读，包含了经验心得、选题指导、参考文献、范文还有格式整理的技巧，对论文写作绝对非常有用，如果对论文还有什么不明白的，可以直接搜索品学论文网上查看对应专业的范文或者直接咨询在线指导老师。【写作论文前必看品学论文网老师总结的论文写作经验】 1.论文写作万不可抄袭。大家着手准备论文时，首先就是寻找参考资料和范文，借助搜索引擎的强大，我们能够在网上搜索到非常多的参考文献和资料，但是来品学论文网的同学们通常遇到的问题就是对参考文献和范文不能合理利用，想偷工减料，直接借用是非常常见的。现在无论是本科论文还是硕士论文都会通过抄袭检测软件查重，直接影响到毕业。所以请大家务必重视。 2.论文需要创新，不能随大流。这点大家都能想到，如果跟你同学的题目或者内容一样，肯定不会的高分，论文的创新可以从提出新的观点，结合案例分析，用一些数据分析工具，结合新的理论等方面进行。 3.如何快速写作论文。如果你仅仅是想毕业，而不是做出杰出的科研成就，那么就少看一些正规的论文写作方法。首先，找出一堆最新的参考文献与范文，最好是近2年的，如果太老旧，肯定在网上传遍了，可能你同学也在用，最近范文可以在品学论文网的数据库中搜下；然后，通过结合多篇文章给自己拟个题目和提纲，与别人的论文区别开来最重要的就是提纲的写作，一定要细分到三级提纲；最后，参考/post/940.html这篇文章对论文的抄袭检测机制做了解，对文章理论部分进行改写，再结合案例做具体的分析描述。以下是品学论文网该专业众多范文中的一篇：矿井提升机变频调速控制系统毕业论文 【论文内容】本论文的研究目标是提升机基于PLC的矢量控制变频调速系统在矿山生产中的实际应用,对现有的调速控制系统进行改造设计,提高精度,在更安全的范围内保证矿山生产的顺利进行。矿井提升系统是一个高强度作业系统,因此对提升机电气传动系统也有更高的要求。矿井提升机调速控制系统硬件部分由变频器、可编程控制器、司机操作台、监视系统及提升机机械传动部分构成。设计中充分考虑到控制系统使用环境恶劣,对电控系统采取了保护和抗干扰措施;软件中加设故障处理子模块,使操作系统更加安全可靠。本调速系统与其它控制系统的不同之处在于,提升机速度给定采用PLC软件编程直接生成S形速度给定曲线,特点是可根据用户需要进行编程,应用灵活,系统为无级调速,调速性能好。本文还给出了提升机调速控制系统数学模型,详细阐述了矢量变换原理,随后由简化的数学模型建立了Simulink下的矢量控制仿真系统,对矢量控制变频调速系统进行仿真。以验证该调速控制系统的可行性。 【英文摘要】 The mine hoist is often been called the throat of mine mountain by people, which is the most important equipments in mine mountain.It is the only road of contactting the ground and the bottom of a well in the whole mineral well. It takes the important carriage responsibility of ore, material and personnel etc. It is crucial for mine hoist that stability and reliability .The electricity controls system of traditional mine hoist exist many safe questions. Although the electron-control system of the elevator through the development of quite a few generation, people carried on an improvement from the machine, electronics, maintenance .etc., obtaining certain result. There are also many other questions in controlling speed by using rotorring resistance in which many AC relaycontactor are used, such as ,too much energy consumption, very complicated controlling circuits, breaks down easily; in addition, the bad condition(dust, pour water and the whereabouts heavy thing of blunt hit etc.) of the spot usage resulted in the function of various machinery fitting and electric element lose efficacy;At last, the artificial mistake of the operation and the limit study to the route of tramcar, make existing the protection can not attain an expectation of result, cause trouble to the promote system ,so colliery accident take place sometimes, endanger life, affectting the mineral well to produce normally. Therefore, the control system of mine hoist speed regulation which develops a high performance is the topic of the utmost urgency.The research target of this thesis is to promote its function of mine hoist by carrying on a reformation to the traditional control system and try to combine the programmable controller (PLC) strong control function with Variable-requency Regulating-speed technology together and apply in mine. This paper introduces the developing situation of the electric controlled system of the mine hoist, analyzes on the features and the functions of the PLC control system, and connecting with the actual conditions, expounds the practicability of the The Variable-frequency Regulating-speed Control System of the Mine Hoist adopting The PLC Control Mode.All functions of the traditional system are reserved in the reformation, andmake good use of the PLC intelligence control function. So raised the system safety and efficiency of the mine.(1) Intensified a safety protection function. The new control system after reformed adopts double redundancy structuresoftware security circle and relay hardware security circle, once one of them working, the safe return then acts. The signal of safe return, such as, overwind, overspeed, decelerate etc, all double protection and assure the system safety protection .(2) Make use of PLC to carry on an intelligence treatment towards running - time retardance dot, highly shorten to promote cycle, raising produce efficiency, can carry out zero creeping but accurate stop.(3) Reliability good, control precision higher .Make use of the PLC to give a reference velocity and raise a control precision. The original system adopting rotor- ring resistance have stage speed regulation, speed regulation performance difference, and fluctuation big, failure rate higher .(4) Raise protection reliability, carry out a numerical type protection. Make use of the PLC implementation numerical relaying protection, raised protection reliability, in the original system many relay are used to protecting the system. The relay is an old style mechanical structure, sometimes the residual magnetism of coil will cause a mis-operation, the new system makes use of current or voltage transmitter to carry out protection through the A/D module , compare with the reference signal, and then send out corresponding guard signal, thus carry out a dependable protection .(5) Make use of the PLC achieve the whole process numerical type stroke control. The old system control precision is low, adaptation capacity difference, protect function weak, just these faults are the important reasons which result in the sever promote accident. The new system makes use of The count module to calculate the bidirectional pulses from encoder, and then do some work, thus we can get position and the speed of the cage at present , also PLC can carry on other protection that have something to do with position and speed of the cage .such as , overwind , overspeed and lose-rope etc.The whole simulation system that The Variable-frequency Regulating-speed Control System of Mine Hoist divide three stages to carry on, first according to the function of the electric control system with match an industrial department of coalthe coal mine appropriation equipments to standardize the technique committee to put forward of the promote machine electric control system standard, make sure the hardware constitutes and software of technique index of the electric control system; Secondly , make use of the strong simulation system of the MATLAB to create the mathematical model of three phase asynchronous motor, set up the simulation model of The Variable-frequency Regulating-speed Control System ;Finally, on those base of work, complete the whole system simulation, analysis simulated data in order to identify whether the systems function can satisfy with the design index or not.After do many work about the electric control ,such as ,Simulation and The promote machine machinery characteristic analysis ;From the results can see the electric control system can attain the design request, the control scheme of the system is reasonable, the function can attain the request of the mine safe production.由于篇幅所限，以上题目对应的毕业论文范文请到【品学论文网】查阅，另外，你可以根据自身需求定制毕业论文写作服务，在线咨询王老师qq【814-952-825】如果您还在为论文的写作烦恼，立刻搜索“品学论文网”获得在线写作指导