電力系統(tǒng)負(fù)荷預(yù)測(cè)及方法(外文翻譯)

1、Power system load forecasting methods and characteristics of Abstract： The load forecasting in power system planning and operation play an important role，with obvious economic benefits， in essence, the electricity load forecasting market demandforecast。 In this paper, a systematic description and an

2、alysis of a variety of load forecastingmethods and characteristics and that good load forecasting for power system has become animportant means of modern management.Keywords:powersystemloadforecastingelectricitymarketconstructionPlanning1.IntroductionLoad forecasting demand for electricity from a kn

3、own starting to consider the political,economic, climate and other related factors, the future demand for electricity to make predictions. Load forecast includes two aspects: on the future demand （power） projections and futureelectricityconsumption（energy） forecast。 Electricitydemandprojectionsdecis

4、iongeneration， transmission and distribution system， the sic of new Capacity; power generating equipment determine the type of prediction (。such as peaking units, base load units， etc。Load forecasting purposes is to provide load conditions and the level of development, while identifying the various

5、supply areas, each year planning for the power consumption for maximum power load and the load of planning the overall level of development of each plan year todetermine the load composition。2。 load forecasting methods and characteristics of2。1 Unit Consumption ActOutput of products in accordance wi

6、th national arrangements, planning and electricity intensity value to determine electricity demand。 Sub-Unit Consumption Act； Product UnitConsumption; and the value of Unit Consumption Act; two. The projection of load before the key is to determine the appropriate value of the product unit consumpti

7、on or unit consumption. Judging fromChinas actual siuaegeneral rule is the product unit consumption increased year by year, the output value unit consumption is declining。 Unit consumption methodadvantages arc： The method is simple， short-torn load forecasting effective. Disadvantages arc: need to d

8、o a lot of painstaking research work, more general, it is difficult to reflect modern economic, political and climate conditions.2.2TrendextrapolationWhen the power load in accordance with time-varying present same kind of upward ordownward trend, and no obvious seasonal fluctuations， but also to fi

9、nd a suitable function curveto reflect this change in trend， you can use the time t as independent variables, timing value of yfor the dependent variable to establish the trend model y = f (t). When the reason to believe that this trend will extend to the future, we assigned the value of the variabl

10、e t need to ， you can getthe corresponding tune series of the future value of the moment. This is the trend extrapolation。Application of the trend extrapolation method has two assumptions:（1) assuming there is nostep Change in load; (2 ）assume that the development of load factors also determine the

11、future development of load and its condition is unchanged or changed little。Select the appropriate trendmodel is the application of the trend extrapolation an important part of pattern recognition methodand finite difference method is to select the trend model arc two basic ways.A linear trend extra

12、polation forecasting method， the logarithmic trend forecasting method,quadratic curve trend forecasting method, exponential curve trend forecasting method， growthcurve of the trend prediction method. Trend extrapolation methodsadvantages arc： only need tohistorical data, the amount of data required

13、for less. The disadvantage is that: If a change in load will cause large errors.2。3 Elastic Coefficient MethodElasticity coefficient is the average growth rate of electricity consumption to GDP ratio of between， according to the gross domestic product growth rate of coefficient of elasticity to be p

14、lanning with the end of the total electricity consumption。 Modules of elasticity law isdetermined on power development from a macro with the relative speed of national economic development， which is a measure of national economic development and an important parameter in electricity demand。 The adva

15、ntages of this method arc: The method is simple, easy tocalculate. Disadvantages arc： need to do a lot of detailed research work.2.4 Regression Analysis MethodRegressionestimateisbasedonpasthistoryofloaddata,buildupamathematicalanalysisof themathematicalmodel。 Of mathematical statistics regressionan

16、alysis of the variables in statistical analysis of observational data in order to achieve load topredict the future. Regression model with a linear regression， multiple linear regression，nonlinear regression and other regression prediction models.Among them, linear regression for themediumtorntoadfo

17、recast.Advantages arc: a higher prediction accuracy for themedium and the use of short-term forecasts. The disadvantage is that: （1) planning level it isdifficult years of industrial and agricultural output statistics;(2）regression analysis can only bemeasured out the level of development of an inte

18、grated electricity load can not be measured out the power supply area of the loading level of development, thus can notbe the specific grid construction plan。2。5 Time Series AnalysisThe load is on the basis of historical data, trying to build a mathematical model, using this mathematical model to de

19、scribe the power load on the one hand this random variable of statistical regularity ofthechangeprocess;theother hand,themathematical model basedonthere-establishment of the mathematical expression of load forecasting type ， to predict the future load。 Time series are mainly autoregressive AR （pmovi

20、ng average MA (q) andself-regression and n3oving average ARMA (pq) and so onThe advantages of these methodsarc： the historical data required for less, work less. The disadvantage is that: There is no change in load factor to consider， only dedicated to the data fitting, the lack of regularity of tre

21、atment isonly applicable to relatively uniform changes in the shortterm load forecasting situation.2。6 Gray model methodGray prediction is a kind of a system containing uncertain factors to predict approach. Gray system theory based on the gray forecasting techniques may be limited circumstances in

22、the data to identify the role of law within a certain period，the establishment of load forecasting models. Isdivided into ordinary gray system model and optimization model for two kinds of gray.Ordinary gray prediction model is an exponential growth model, when the electric load in strict accordance

23、 with exponentially growing, this method has high accuracy and required less sample data to calculate simple and testable etcdrawback is that for a change in volatility Thepower load， the prediction error largo, does not meet actual needs。 And the gray modeloptimization can have ups and downs of the

24、 original data sequence transformed into increased exponentially increasing regularity changes in sequence, greatly improving prediction accuracyand the gray model method of application. Gray Model Law applies to short-torn load forecast 。Gray predicted advantages: smaller load data requirements，wit

25、hout regard to the distribution of laws and do not take into account trends, computing convenient, short-term forecasts of high precision, easy to test。 Drawbacks: First， when the data the greater the degree of dispersion，namely, the greater the gray level data， prediction accuracy is worse; 2 is no

26、t very suitable for the longterm power system to push a number of years after the forecast。2。7 Delphi MethodThe Delphi method is based on the special knowledge of direct experience， research problems of judgment, a method for prediction of， also called experts investigation. Delphi method has feedba

27、ck, anonymity and statistical characteristic。Delphi method advantage can accelerate prediction speed and save prediction Cost; (2)can get different but valuable ideas and opinions； （3）suitable for longterm forecasts in historical data，insufficient or unpredictablefactors is particularly applicable m

28、ore。 Detect is: (1）the load forecasting far points area may not reliable; （2)the expert opinions sometimes may not complete or impractical。Expert System ApproachExpert system prediction is stored in the database over the past tow years, even decades，the Hourly load and weather data analysis, which b

29、rings together experienced staff knowledge load forecasting, extract the relevant rules, according to certain rules, load prediction. Practice has proved that accurate load forecasting requires not only hightech support, but also need to reconcile the experience and wisdom of mankind itself：Therefor

30、e, youneedexpert systemssuchtechnologies 。Expertsystemsapproachisanon-quantifiablehuman experience translated into a better way But experts systems analysis itself is a time-consuming process, and some complex factors（such as weather factors ）, even though aware of its load impact, htt to accurately

31、 and quantitatively determine their influence on the load area is also very difficult. Expert system for forecasting method suitable for medium and longterm load forecast。The advantages of this method: (1）can bring together multiple expert knowledge and experience to maximize the ability of experts;

32、 （2) possession of data， information and mort factors toconsider a more comprehensive and beneficial to arrive at mart accurate conclusions。 The disadvantage is that： （1）do not have the selflearning ability， subject to the knowledge storedin thedatabaselimits the total;（2) pairs of unexpected incide

33、nts and poor adaptability to changing conditionsNeural Network MethodNeural network （ANN, Artificial Neural Network) forecasting techniques to mimic the human brain to do intelligent processing， a large number of non-structural。 non-deterministiclaws of adaptive function。 ANN used in shortterm load

34、forecasting and longterm loadforecast than that applied to be mart appropriate. Because shortterm load changes can be regarded as a stationary random process. And longterm load forecasting may be due to political, economic and other major fuming point leading to a mathematical modelbased damag。Advan

35、tages ar1) to mimic the human brai， intelligence processin；（2a large number of non-structural. non-adaptive function of the accuracy of the law; (3)with the information memory， selflearning, knowledge, reasoning and optimization of computing features. The disadvantage is that:（1） the determination o

36、f the initial value can not take advantage of existing system information， easily trapped in local minimum of the state ； (2） neural network learning process is usually slow, poor adaptability to sudden events.2。10 Optimum Combination Forecasting MethodOptimal combination has two meanings： First, se

37、veral forecasting methods from the resultsobtained by selecting the appropriate a0cight in the weighted average；2 refers to the comparisonof several prediction methods, choose the best or the degree of preparation and the standarddeviation of the smallest prediction model forecast 。 For the combined

38、 forecasting method must also noted that the combined forecast is a single forecasting model can not completely correct to describe the changes of the amount predicted to play a role. One can fully reflect the actual law of development of the model predictions agree well with the combination forecas

39、ting method than predicted good results. This method has the advantage: To optimize the combination of a widerange of information on a single prediction model， consider the impact of information is also mart comprehensiv，so it can effectively improve the predictio。The disadvantage is tha（1) the weig

40、ht is difficult to determine;（2） all possible factors that play a role in the future, all included in the model, to a certain extent, limit the prediction accuracy improved.2.11 Wavelet analysis and forecasting techniquesWavelet analysis is a time-domainfrequency domain analysis method, it is in the

41、 timedomain and frequency domain at the same time has good localization properties, and canautomatically adjust according to the signal sampling frequency of high and low density, it is castto capture and analysis of weak signals and signal，images of any small parts。The advantage is:Can the differen

42、t frequency components gradually refined using a sampling step ， which can be gathered in any of the details of the signal, especially for singular signal is very sensitive to the treatment well or mutation weak signals, their goal is to a signal information into waveletcoefficients， whichcaneasilyb

43、edealtwith,storage,transmission， analysisorforthe reconstruction of the original signal. These advantages determine the wavelet analysescan be effectively applied to load forecasting issues.3. ConclusionLoad forecasting is the electric power system scheduling, realtime control, operation plan and de

44、velopment planning， the premise is a grid dispatching departments and planning departments must have the basic information 。 Improve load forecasting technology level, be helpful for program management, reasonable arrangement of the electricity grid operation mode for the maintenance plan and the cr

45、ew，to section coal， fuelefficient and reduce generating cost, be helpful for formulate rational power construction planning of the power system，improve the economic benefit and social benefit. Therefore, the load forecast has becomea power system management modernization realization of the important

46、 content.電力系統(tǒng)負(fù)荷猜測(cè)及方法摘要：負(fù)荷猜測(cè)在電力系統(tǒng)規(guī)劃和運(yùn)行方面發(fā)揮的重要作用，具有明顯的經(jīng)濟(jì)效益,負(fù)荷預(yù) 測(cè)實(shí)質(zhì)上是對(duì)電力市場(chǎng)需求的猜測(cè)。該文系統(tǒng)地介紹和分析了各種負(fù)荷猜測(cè)的方法及特點(diǎn)，并指出做好負(fù)荷猜測(cè)己成為實(shí)現(xiàn)電力系統(tǒng)管理現(xiàn)代化的重要手段。1。 引言（功率）的頂測(cè)和將來(lái)用電量 (能量)的頂測(cè).發(fā)電設(shè)備的類(lèi)型（如調(diào)峰機(jī)組、基荷機(jī)組等)。負(fù)荷猜測(cè)的日的就是供應(yīng)負(fù)荷進(jìn)展?fàn)顩r及水 確定各規(guī)劃年用電負(fù)荷構(gòu)成。2。負(fù)荷猜測(cè)的方法及特點(diǎn)2.1 單耗法.單耗法分“產(chǎn)品單耗法和“產(chǎn)值單耗法兩種.接受“單耗法猜測(cè)負(fù)荷前的關(guān)鍵是確定適當(dāng)?shù)漠a(chǎn)品單耗或產(chǎn)值單耗。 從我國(guó)的實(shí)際狀況來(lái)看，一般規(guī)律是產(chǎn)品

47、單耗逐年上升,產(chǎn)值單耗逐年卜降。單耗法的優(yōu)點(diǎn).缺點(diǎn)是:需做大量細(xì)致的調(diào)研工作，比較籠統(tǒng),很難反映現(xiàn)代經(jīng)濟(jì)、政治、氣候等條件的影響。2。2 趨勢(shì)外推法當(dāng)電力負(fù)荷依時(shí)間變化呈現(xiàn)某種上升或下降的趨勢(shì)，并且無(wú)明顯的季節(jié)波動(dòng)，又能找 t y 為因變量，建立趨勢(shì)模型Y=（。當(dāng)有理由信任這種趨勢(shì)能夠延長(zhǎng)到將來(lái)時(shí)，賜予變量t 所需要設(shè)條件1; (其條件是不變或變化不大.選擇合適的趨勢(shì)模型是應(yīng)用趨勢(shì)外推法的重要環(huán)節(jié),圖形識(shí)別法和差分史數(shù)據(jù)、所需的數(shù)據(jù)量較少。缺點(diǎn)是：假如負(fù)荷消滅變動(dòng)，會(huì)引起較大的誤差。2。 3 彈性系數(shù)法彈性系數(shù)是電量平均增長(zhǎng)率與國(guó)內(nèi)生產(chǎn)總值之間的比值,依據(jù)國(guó)內(nèi)生產(chǎn)總值的增長(zhǎng)速度結(jié)合彈性系數(shù)得到規(guī)劃期末的總用電量進(jìn)展的相對(duì)速度，它是衡量國(guó)民經(jīng)濟(jì)進(jìn)展和用電需求的重要參數(shù)。該方法的優(yōu)點(diǎn)是:方法簡(jiǎn)潔,易于計(jì)算。缺點(diǎn)是：需做大量細(xì)致的調(diào)研工作.2.4 回歸分析法 (1)規(guī)劃水平年的工農(nóng)業(yè)總產(chǎn)值很難具體統(tǒng)計(jì);（2)用回歸