A research on short term load forecasting problem applying improved grey dynamic model

The grey dynamic model GM(1, 1), which is based on the grey system theory, has recently emerged as a powerful tool for short term load forecasting (STLF) problem. However, GM(1, 1) is only a first order single variable grey model, the forecasted accuracy is unsatisfactory when original data show great randomness. In this paper, we propose improved grey dynamic model GM(2, 1), a second order single variable grey model, to enhance the forecasted accuracy. Then it is applied to improve STLF performance. We provide a viewpoint that the derivative and background value of GM(2, 1) model can be expressed in grey number. Then cubic spline function is presented to calculate the derivative and background value in grey number interval. We call the proposed model as 3spGM(2, 1) model. Additionally, Taylor approximation method is applied to 3spGM(2, 1) for achieving the high forecasted accuracy. The improved version is defined as T-3spGM(2, 1). The power system load data of ordinary and special days are used to validate the proposed model. The experimental results showed that the proposed model has better performance for STLF problem.