Study Of Daily Load Forecast Based On Fuzzy Set Technology And Neural Network

The daily load forecast of electric power system is an important routine for power dispatch departments. Its precision will influence the economic and secure operation of power systems and quality of power supply. The features of daily load forecast can be generalized as followings:many data need to be forecasted, the physical factors which influence forecast are complicated and random, and high precision of forecast is demanded. This thesis covers two aspects:the process method of daily load data and the research of forecast model.Firstly, the load of power system is an unsteady stochastic process, whose observed value may exist some "unhealthy data" due to the effect of various factors. These unhealthy data, participating the training of neural network intermingled with normal data, badly affect the accuracy of load forecasting. This paper finds out the mean value and variance of load sequence in a period of time based on statistics and then works out the bias ratio of every point in load sequence using corresponding calculation formula and at the same time compares it with threshold value so that "unhealthy data" can be removed and accurate and effective load forecasting can be...