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中长期电量预测的傅里叶马尔科夫修正模型

2016-11-30李欣然陈鸿琳冷华陈国民

湖南大学学报·自然科学版 2016年10期

李欣然+陈鸿琳+冷华+陈国民

摘 要:灰色模型在中长期电量预测中只对电量呈近似指数规律单调增长的序列才有较高的预测精度.随着电量变化随机波动性的增强,建立新的修正预测模型是十分必要的.针对灰色模型抗干扰能力差的问题,提出了灰色预测的傅里叶马尔科夫修正模型,先利用傅里叶级数法,提取周期信息,优化电量变化的指数率,再采用马尔科夫链法,将电量波动随机性嵌入模型之中,从而对灰色预测的原始残差进行二重修正,提高预测模型的适应性和灵活性.通过实例分析以及对比验证表明,该模型有效地提高了预测精度.

关键词:电量预测; 灰色模型; 残差修正; 傅里叶级数; 马尔科夫链

中图分类号 TM715 文献标识码 A

文章编号:1674-2974(2016)10-0062-08

Abstract:Gray model is widely used in mid-long term electricity demand forecasting, but the model fits exponentially increasing data more precisely. Due to China's economic growth rate fluctuations, the increase in electricity consumption is slowing down, and electricity varies stochastically. So it is necessary to propose a new model to reflect the new situation. To solve the problem of the poor anti-interference ability of grey model, this paper proposes a model with Fourier series and Markov theory residual error correction based on grey model. This model applies Fourier series method to optimize electricity changing rate, and Markov chain method to embed the random property in gray forecasting model for doubly correcting the residual error, which can improve the adaptability and flexibility. The proposed model is verified by actual load data, and it indeed improves the forecasting accuracy.

Key words:load forecasting; grey model; residual error correction; Froier series; Markov chain theory

中长期电量预测多指年度预测和月度预测,对电力部门的发展规划有重要意义,电量预测有利于提高电网运行的安全性和经济性.当经济增长,用电需求呈逐年递增的趋势时,灰色预测模型[1]能较好地以指数形式拟合中长期用电量情况.但是用电量还受到政治、经济事件以及气候因素的影响,具有一定的随机性与波动性,电量并不是按照绝对的指数规律逐年递增,近年来却出现了增速放缓的现象,有的地区甚至出现负增长,此时若不对灰色模型预测结果进行修正,会产生较大的误差.

实际上,对时间序列残差的修正由来已久亦非常普遍[2-3],电力系统应用中多先对残差绝对值……

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