Combination Forecasting Model In The Zhongshan Power And Long-term Load Forecasting System

Long-term load forecast is the basic issue to ensure the city electric-net plan of power. It provide indispensable basic data and its accuracy level influence the construction of power grid directly. But it's too difficult to have accurate evaluation,because the factor were very complex which will influence the power's change. factors coming from society,politics,economics even weather must be considered.In the thesis,the detailed aspects and characteristics of several forecast methods used in load forecast are discussed. Also,comparison of advantages,disadvantages and considered applicable extent are made amoung these methods and then it come to a conclusion. Besides,the skill applied in present electrical long-term load forecast is also analysised in it. In order to improve the precision of electric power system load forecasting,the linear regression combined forecast models is put forward,according to the specific of Zhongshan power long-term load forecast. If using the model,there are sevral key points and difficulties. One is how to select several best forecast models to combine the result of output from these models. Another is the evaluaion of weight-modulus about every single forecast model. And then is how to solve the problem of negative weight-modulus. This passage suggest to select the best forecast model by gray related analyze and redundant examine. After comparion,the gray forecast model,logistic model,Compert incremental curve are used in the load forecast of zhongshan area every year. It make full use of the characteristics of the gray forecasr model which require few data disregard the distributing law and changing trend and is easy to operate and checking.Moreover, it combine the specifics of Compertz- incremental Curve and logistic model. We will consider the sum of wucha pingfan of combination forecasting as a goal. When it reaches min,we will get some weight-modulus for several best models. If it has non-negative weight-modulus,we will use equivalent weight recurrence combination forecast mode to get weight-modulus.After the discussion of the load forecast method,the load forecast of a specific power system is carried out in Zhongshan region. This utility demonstrates the feasibility of the method.