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供配电系统外文翻译

2024-07-16 来源:爱问旅游网

PowerSupply and Distribution System

ABSTRACT:Thebasic function of the electric power system is to transport theelectric power towards customers. The l0kV electric distribution netis a key point that connects the power supply with the electricityusing on the industry, business and daily-life. For the electricpower, allcostumers expect to pay the lowest price for the highestreliability, but don't consider that it's self-contradictory in theco-existence of economy and reliable.To improve the reliability of the power supply network, we must increase the investment cost of thenetwork construction But, if the cost that improve the reliability ofthe network construction, but the investment on this kind ofconstruction would be worthless if the reducing loss is on thepower-off is less than the increasing investment on improving thereliability .Thus we find out a balance point to make the mosteconomic,between the investment and the loss by calculating theinvestment on power net and the loss brought from power-off.

KEYWORDS:powersupply and distribution, power distribution reliabilityreactivecompensation, load distribution

Therevolution of electric power system has brought a new big roundconstruction,which is pushing the greater revolution of electricpower technique along with the application of new technique andadvanced equipment. Especially, the combination of the informationtechnique and electric power technique, to great ex- tent, hasimproved reliability on electric quality and electric supply. Thetechnical development decreases the cost on electric construction anddrives innovation of electric network. On the basis of national andinternatio- nal advanced electric knowledge, the dissertationintroduces the research hotspot for present electric power sy- etemas following.

Firstly,This dissertation introduces the building condition of distributionautomation(DA), and brings forward two typical construction modes onDA construction, integrative mode and fission mode .It emphasize theDA structure under the condition of the fission mode and presents thesystem configuration, the main station scheme, the feeder scheme, theoptimized communication scheme etc., which is for DA researchreference.

Secondly,as for the (DA) trouble measurement, position, isolation and resume,This dissertation analyzes the changes of pressure and current forline problem, gets math equation by educing phase short circuit andproblem position under the condition of single-phase and works outequation and several parameter s U& , s I& and e I& tableon problem . It brings out optimized isolation and resume plan,realizes auto isolation and network reconstruction, reduces the poweroff range and time and improves the reliability of electric powersupply through problem self- diagnoses and self-analysis. It alsointroduces software flow and use for problem judgement and

setsa model on network reconstruction and computer flow.

Thirdly,electricity system state is estimated to be one of the key techniquesin DA realization. The dissertation recommends the resolvent of badmeasurement data and structure mistake on the ground of describingstate estimate way. It also advances a practical test and judging wayon topology mistake in state estimate about bad data test andabnormity in state estimate as well as the problem and effect on baddata from state measure to state estimate .As for real time monitorand control problem, the dissertation introduces a new way to solvethem by electricity break and exceptional analysis, and the way hasbeen tested in Weifang DA.

Fourthly,about the difficulty for building the model of load forecasting, bigparameter scatter limit and something concerned, the dissertationintroduces some parameters, eg. weather factor, date type and socialenvironment effect based on analysis of routine load forecasting andmeans. It presents the way for electricity load forecasting foundedon neural network(ANN),which has been tested it’s validity byexample and made to be good practical effect.

Fifthly,concerning the lack of concordant wave on preve nting concordant waveand non-power compensation and non-continuity on compensation, thereis a topology structure of PWM main circuit and nonpower theory onactive filter the waves technique and builds flat proof on the groundof Saber Designer and proves to be practical. Meanwhile, it analyzesand designs the way of non-power need of electric network tre- ndsand decreasing line loss combined with DA, which have been tested itsobjective economic benefit throu- gh counting example.

Sixthly,not only do the dissertation design a way founded on the magrginalelectric price fitted to our present national electric power marketwith regards to future trends of electric power market in China andfair trade under the government surveillance, that is groupcompetitio n in short-term trade under the way of grouped price andquantity harmony, but also puts forward combination arithmetic, mathmodel of trading plan and safty economical restriction. It can solvethe original contradiction between medium and long term contractprice and short term competitive price with improvement oncompetitive percentage and cut down the unfair income difference ofelectric factory, at the same time, it can optimize the electriclimit for all electric factories and reduce the total purchase chargeof electric power from burthen curve of whole electric marketnetwork.

Thedistribution network is an important link among the power system. Itsneutral grounding modeand operation connects security and stability of the power systemdirectly. At the same time, the problem about neutral grounding isassociated with national conditions, natural environment, devicefabrication and operation. For example, the activity situation of thethunder and lightning, insulating structure and the peripheralinterference will influence the choice of neutral grounding

modeConversely, neutral grounding mode affects design, operation, debugsand developing. Generally in the system higher in grade in thevoltage, the insulating expenses account for more sizable proportionat the total price of the equipment. It is very remarkable to bringthe economic benefits by reducing the insulating level. Usually suchsystem adopt the neutral directly grounding and adopt theautoreclosing to guarantee power supply reliability. On the contrary,the system which is lower in the voltage adopts neutral nonegrounding to raise power supply reliability. So it is an importantsubject to make use of new- type earth device to apply to thedistribution network under considering the situation in such factorsof various fields as power supply reliability, safety factor,over-voltage factor, the choice of relay protection, investment cost,etc.

Themain work of this paper is to research and choice the neutralgrounding mode of the l0kVdistribution network. The neutral grounding mode of the l0kV networkmainly adopts none grounding, grounding by arc suppressing coil,grounding by reactance grounding and directly grounding. The bestgrounding mode is confirmed through the technology comparison. It canhelp the network run in safety and limit the earth electric arc byusing auto-tracking compensate device and using the line protectionwith the detection of the sensitive small ground current. The paperintroduces and analyzes the characteristic of all kind of groundingmodes about l0kV network at first. With the comparison withtechnological and economy, the conclusion is drawn that the improvedarc suppressing coil grounding mode shows a very big developmentpotential.

Then,this paper researches and introduces some operation characteristicsof the arc suppressing coil grounding mode of the l0kV distributionnetwork. And then the paper put emphasis on how to extinguish theearth electric arc effectively by utilizing the resonance principle.This paper combines the development of domestic and internationaltechnology and innovative achievement, and introduces the computerearth protection and autotracking compensate device. It proves thatthe improved arc suppressing coil grounding mode have betteroperation characteristics in power supply reliability, personalsecurity, security of equipment and interference of communication.The application of the arc suppressing coil grounding mode is alsoresearched in this paper.

Finally,the paper summarizes this topic research. As a result of thedomination of the arc suppressing coil grounding mode, it should bemore popularized and applied in the distribution network in thefuture.The way of thinking, project and conclusions in this thesishave effect on the research to choose the neutral grounding mode notonly in I0kV distribution network but also in other power system..

Thebasic function of the electric power system is to transport theelectric power towards customers. The l0kV electric distribution netis a key point that connects the power supply with

theelectricity using on the industry, business and daily-life. For theelectric power, all costumers expect to pay the lowest price for thehighest reliability, but don't consider that it's self-contradictoryin the co-existence of economy and reliable. To improve thereliability of the power supply network, we must increase theinvestment cost of the network con- struction But, if the cost thatimprove the reliability of the network construction, but theinvestment on this kind of construction would be worthless if thereducing loss is on the power-off is less than the increasinginvestment on improving the reliability .Thus we find out a balancepoint to make the most economic, between the investment and the lossby calculating the investment on power net and the loss brought frompower-off. The thesis analyses on the economic and the reliable ofthe various line modes, according to the characteristics various linemodes existed in the electric distribution net in foshan..

First,the thesis introduces as the different line modes in the l0kVelectric distribution net and in some foreign countries. Making itclear tow to conduct analyzing on the line mode of the electricdistribution net, and telling us how important and necessary thatanalyses are.

Second,it turns to the necessity of calculating the number of optimizationsubsection, elaborating how it influences on the economy andreliability. Then by building up the calculation mode of the numberof optimization subsection it introduces different power supplyprojects on the different line modes in brief. Third, it carries onthe calculation and analyses towards the reliability and economy ofthe different line modes of electric distribution net, describingdrafts according by the calculation. Then it makes analysis anddiscussion on the number of optimization subsection.

Atlast, the article make conclusion on the economy and reliability ofdifferent line modes, as well as, its application situation.Accordion to the actual circumstance, the thesis puts forward thebeneficial suggestion on the programming and construction of the l0kVelectric distribution net in all areas in foshan. Providing the basictheories and beneficial guideline for the programming design of thelOkV electric distribution net and building up a solid net,reasonable layout, qualified safe and efficiently-worked electricdistribution net.

References

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[2]Jiecai Liu. Factories power supply design guidance [M]. MachineryIndustry Publishing House.1999.12
[3]Power supply and distribution system design specifications[S].Chinaplans Press. 1996
[4]Low-voltage distribution design specifications [S].China plans Press.

1996.6

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