Autocorrelation Based Weighing Strategy for Short-Term Load Forecasting with the Self-Organizing Map

In this paper, we introduce a load forecasting method for short-term load forecasting which is based on a two-stage hybrid network with weighted self-organizing maps (SOM) and autoregressive (AR) model. In the first stage, a weighted SOM network is applied to split the past dynamics into several clusters in an unsupervised manner. Then in the second stage, a local linear AR model is associated with each cluster to fit its training data in a supervised way. Though this method can be used for forecasting any time series, it is best suited for processes which are non-linear and non-stationary and show cluster effects, such as the electricity load time series. Data of the electricity demand from Britain and Wales is used to verify the effectiveness of the learning and prediction of the proposed method.