基于形态相似准则的曲线拟合算法及其在超短期负荷预测中的应用

提出了一种基于形态相似准则的曲线拟合算法，以保证拟合曲线与实际曲线的形态最相似为准则，同时引入时间影响因子。将拟合曲线方程参数的求解转化为约束极值问题，利用罚函数法将该约束极值问题转化为无约束极值问题，采用Powell方法求解该无约束极值问题。利用该算法对超短期负荷预测中的曲线拟合预测方法进行了改进，研究结果表明，该算法在保证运算速度的同时，提高了总体预测准确性和拐点处的预测准确性。

A Shape Similarity Criterion Based Curve Fitting Algorithm and Its Application in Ultra-Short-Term Load Forecasting

Based on shape similarity criterion, a new curve fitting algorithm is proposed in which the criterion that to ensure the shape of the fitted curve should be most similar to that of actual curve is abided and at the same time the time-concerning impact factor is inducted; the solution of parameters of fitting curve equation is transformed into constrained minimization problem, and by use of penalty function method this constrained minimization problem is transformed into unconstrained minimization problem, then this unconstrained minimization problem is solved by Powell method. Using the proposed algorithm the curve fitting forecasting method in ultra-short-term load forecasting is improved. Research results show that the proposed algorithm can improve overall forecasting accuracy and forecasting accuracy at inflexion point while the calculation speed is ensured.