发布时间 : 星期四 文章某轧钢厂供电系统设计更新完毕开始阅读24c35b45814d2b160b4e767f5acfa1c7ab008257
.
致谢
我做的是轧钢厂供配电系统设计.通过这次毕业设计， 我加深了对工厂供电知识的理解，基本上掌握了进行一次设计所要经历的步骤，我进行课题分析、查资料，进行设计，整理说明书到最后完成整个设计。作为大学阶段一次重要的学习经历我感觉自己受益非浅， 同时深深的感觉的自己的学习能力在不断提高，几个月的时间就这样匆匆的过去了，再指导老师我经过多少个白天，黑夜，我刻苦研究。这次设计使我对工厂供电有了新的认识， 对工厂供配电设计由一无所知到现在的一定程度的掌握，起到了非常重要的作用，对刘文庄老师的关心，指导有感于心， 事实上这次设计对我们的锻炼是多方面的，除了对设计过程熟悉外，我们还进一步提高了作图，说明书编辑，各种信息的分析，对 WORD 文档的使用等多方面的能力。轧钢厂供配电系统的设计已经按照设计原则要求设计完了， 虽然能够满足设计任务书的要求，但是我认为还要提高和改进的地方还有很多。在细节方面， 还有许多需要精雕细琢的地方，这次没有能够深入下去。希望以后有机会能够进一步。
在这次设计的过程中本人得到了许多老师的精心指导和帮助。在此我要对给予我帮助的老师表示感谢，没有他们的悉心指导我就不会更好的完成设计任务，特别是老师对设计提出了许多宝贵的意见和建议，使我解决了许多设计中存在的许多问题.在此向他们致以最诚恳的谢意！同时感谢学校给予我们的这次设计机会。
感谢亲爱的华北科技学院将我培养为一名合格的大学生，还要感谢各位专家在百忙当中抽出时间来批阅我们论文并提出宝贵意见。
最后向所有关心和帮助过我的人表示诚挚的祝福，祝愿华北科技学院明天更美好。
..
.
附录：
附录1.外文文献及翻译
Power Supply and Distribution System
ABSTRACT: The basic function of the electric power system is to transport the electric power towards customers. The l0kV electric distribution net is a key point that connects the power supply with the electricity using on the industry, business and daily-life. For the electric power, allcostumers expect to pay the lowest price for the highest reliability, but don't consider that it's self-contradictory in the co-existence of economy and reliable.To improve the reliability of the power supply network, we must increase the investment cost of the network construction But, if the cost that improve the reliability of the network construction, but the investment on this kind of construction would be worthless if the reducing loss is on the power-off is less than the increasing investment on improving the reliability .Thus we find out a balance point to make the most economic,between the investment and the loss by calculating the investment on power net and the loss brought from power-off.
KEYWORDS: power supply and distribution, power distribution reliability，reactive compensation, load distribution
The revolution of electric power system has brought a new big round construction,which is pushing the greater revolution of electric power technique along with the application of new technique and advanced equipment. Especially, the combination of the information technique and electric power technique, to great ex- tent, has improved reliability on electric quality and electric supply. The technical development decreases the cost on electric construction and drives innovation of electric network. On the basis of national and internatio- nal advanced electric knowledge, the dissertation introduces the research hotspot for present electric power sy- etem as following.
Firstly, This dissertation introduces the building condition of distribution automation(DA), and brings forward two typical construction modes on DA construction, integrative mode and fission mode .It emphasize the DA structure under the condition of the fission mode and presents the system configuration, the main station scheme, the feeder scheme, the optimized communication scheme etc., which is for DA research reference.
..
.
Secondly, as for the (DA) trouble measurement, position, isolation and resume, This dissertation analyzes the changes of pressure and current for line problem, gets math equation by educing phase short circuit and problem position under the condition of single-phase and works out equation and several parameter s U& , s I& and e I& table on problem . It brings out optimized isolation and resume plan, realizes auto isolation and network reconstruction, reduces the power off range and time and improves the reliability of electric power supply through problem self- diagnoses and self-analysis. It also introduces software flow and use for problem judgement and sets a model on network reconstruction and computer flow.
Thirdly, electricity system state is estimated to be one of the key techniques in DA realization. The dissertation recommends the resolvent of bad measurement data and structure mistake on the ground of describing state estimate way. It also advances a practical test and judging way on topology mistake in state estimate about bad data test and abnormity in state estimate as well as the problem and effect on bad data from state measure to state estimate .As for real time monitor and control problem, the dissertation introduces a new way to solve them by electricity break and exceptional analysis, and the way has been tested in Weifang DA.
Fourthly, about the difficulty for building the model of load forecasting, big parameter scatter limit and something concerned, the dissertation introduces some parameters, eg. weather factor, date type and social environment effect based on analysis of routine load forecasting and means. It presents the way for electricity load forecasting founded on neural network(ANN),which has been tested it’s validity by example and made to be good practical effect.
Fifthly, concerning the lack of concordant wave on preve nting concordant wave and non-power compensation and non-continuity on compensation, there is a topology structure of PWM main circuit and nonpower theory on active filter the waves technique and builds flat proof on the ground of Saber Designer and proves to be practical. Meanwhile, it analyzes and designs the way of non-power need of electric network tre- nds and decreasing line loss combined with DA, which have been tested its objective economic benefit throu- gh counting example.
Sixthly, not only do the dissertation design a way founded on the magrginal electric price
..
.
fitted to our present national electric power market with regards to future trends of electric power market in China and fair trade under the government surveillance, that is group competitio n in short-term trade under the way of grouped price and quantity harmony, but also puts forward combination arithmetic, math model of trading plan and safty economical restriction. It can solve the original contradiction between medium and long term contract price and short term competitive price with improvement on competitive percentage and cut down the unfair income difference of electric factory, at the same time, it can optimize the electric limit for all electric factories and reduce the total purchase charge of electric power from burthen curve of whole electric market network.
The distribution network is an important link among the power system. Its neutral grounding mode and operation connects security and stability of the power system directly. At the same time, the problem about neutral grounding is associated with national conditions, natural environment, device fabrication and operation. For example, the activity situation of the thunder and lightning, insulating structure and the peripheral interference will influence the choice of neutral grounding mode Conversely, neutral grounding mode affects design, operation, debugs and developing. Generally in the system higher in grade in the voltage, the insulating expenses account for more sizable proportion at the total price of the equipment. It is very remarkable to bring the economic benefits by reducing the insulating level. Usually such system adopt the neutral directly grounding and adopt the autoreclosing to guarantee power supply reliability. On the contrary, the system which is lower in the voltage adopts neutral none grounding to raise power supply reliability. So it is an important subject to make use of new- type earth device to apply to the distribution network under considering the situation in such factors of various fields as power supply reliability, safety factor, over-voltage factor, the choice of relay protection, investment cost, etc.
The main work of this paper is to research and choice the neutral grounding mode of the l0kV distribution network. The neutral grounding mode of the l0kV network mainly adopts none grounding, grounding by arc suppressing coil, grounding by reactance grounding and directly grounding. The best grounding mode is confirmed through the technology comparison. It can help the network run in safety and limit the earth electric arc by using auto-tracking compensate device and using the line protection with the detection of the
..