Hybrid partial least squares and neural network approach for short-term electrical load forecasting

Intelligent systems and methods such as the neural network (NN) are usually used in electric power systems for short-term electrical load forecasting. However, a vast amount of electrical load data is often redundant, and linearly or nonlinearly correlated with each other. Highly correlated input data can result in erroneous prediction results given out by an NN model. Besides this, the determination of the topological structure of an NN model has always been a problem for designers. This paper presents a new artificial intelligence hybrid procedure for next day electric load forecasting based on partial least squares (PLS) and NN. PLS is used for the compression of data input space, and helps to determine the structure of the NN model. The hybrid PLS-NN model can be used to predict hourly electric load on weekdays and weekends. The advantage of this methodology is that the hybrid model can provide faster convergence and more precise prediction results in comparison with abductive networks algorithm. Extensive testing on the electrical load data of the Puget power utility in the USA confirms the validity of the proposed approach.     

Hybrid partial least squares and neural network approach for short-term electrical load forecasting

Intelligent systems and methods such as the neural network （NN） are usually used in electric power systems for short-term electrical load forecasting. However, a vast amount of electrical load data is often redundant, and linearly or nonlinearly correlated with each other. Highly correlated input data can result in erroneous prediction results given out by an NN model. Besides this, the determination of the topological structure of an NN model has always been a problem for designers. This paper presents a new artificial intelligence hybrid procedure for next day electric load forecasting based on partial least squares （PLS） and NN. PLS is used for the compression of data input space, and helps to determine the structure of the NN model. The hybrid PLS-NN model can be used to predict hourly electric load on weekdays and weekends. The advantage of this methodology is that the hybrid model can provide faster convergence and more precise prediction results in comparison with abductive networks algorithm. Extensive testing on the electrical load data of the Puget power utility in the USA confirms the validity of the proposed approach.     

Neural-based electricity load forecasting using hybrid of GA and ACO for feature selection

Due to deregulation of electricity industry, accurate load forecasting and predicting the future electricity demand play an important role in the regional and national power system strategy management. Electricity load forecasting is a challenging task because electric load has complex and nonlinear relationships with several factors. In this paper, two hybrid models are developed for short-term load forecasting (STLF). These models use “ant colony optimization (ACO)” and “combination of genetic algorithm (GA) and ACO (GA-ACO)” for feature selection and multi-layer perceptron (MLP) for hourly load prediction. Weather and climatic conditions, month, season, day of the week, and time of the day are considered as load-influencing factors in this study. Using load time-series of a regional power system, the performance of ACO?+?MLP and GA-ACO?+?MLP hybrid models is compared with principal component analysis (PCA)?+?MLP hybrid model and also with the case of no-feature selection (NFS) when using MLP and radial basis function (RBF) neural models. Experimental results and the performance comparison with similar recent researches in this field show that the proposed GA-ACO?+?MLP hybrid model performs better in load prediction of 24-h ahead in terms of mean absolute percentage error (MAPE).     

电力大数据下的短期电力负荷预测

电力产业是国民工业系统中重要的产业。在电网运行管理中,对于负荷预测具有非常重要的作用。更加准确的电力负荷预测可以为电网的安全稳定运行、实时进行电网负荷的调度提供了重要依据。特别是在经济方面,精确的电力负荷预测可以优化发、用电电网调度计划,合理调度和分配资源,从而起到使社会效益、经济效益最大化的作用。然而随着中国经济的飞速发展,对电力的需求不断增长,电力负荷本身受诸多因素以及政策影响比如日期、天气、气候、市场等其他因素,这些因素更大大加大了准确进行电力负荷预测的困难性。一直以来,人们一直都致力于提高电力负荷预测的准确性,人工神经网络算法具有泛化、学习能力强等优点,现在该算法已在电力负荷预测领域中得到了广泛应用,并且取得了良好的效果。近年来,人工神经网络领域取得重大突破,涌现出一个新的深度学习研究领域。本文就是基于最新发展的人工神经网络算法,结合实际地区电网数据研究了短期电力负荷预测的相关问题。     

基于过程神经元网络的动态预测模型及其应用

〗针对动态系统过程预测预报问题，提出了一种基于过程神经元网络的动态预测方法．过程神经元网络的输入/输出均可以是时变函数，其时空聚合运算和激励可同时反映时变输入信号的空间聚合作用和输入过程中的阶段时间累积效应．基于过程神经元网络的动态预测模型能同时满足对系统的非线性辨识和过程预测，在机制上对动态预测预报问题有较好的适应性．文中给出了基于函数基展开和梯度下降法的学习算法，以电力负荷预报为例验证了模型和算法的有效性．     

灰色变异粒子群算法在电力负荷预测中的应用

由于电力负荷量是电力系统发展的基础,因此提高电力负荷量预测的准确性有利于电力系统的快速发展. 本文利用粒子群算法优化参数的良好性能和灰色预测法适合预测不确定因素影响系统的优势,提出了灰色变异粒子群组合预测模型来预测电力负荷量,提高了电力负荷预测的精度,并通过实例对组合预测模型的预测精度和有效性进行了分析. 结果表明,此组合预测模型的精度优于单一的灰色预测模型,且优于其他几种预测算法,该组合模型能很好地预测电力负荷量,为电力系统的决策和发展提供了可靠的科学数据.     

日电力负荷的分时段多模型组合预测

日电力负荷预测是电力市场运营的基本内容。当前大多数预测方法对不同时段往往采用相同的预测模型和算法,而较少考虑不同时段的负荷组成及特征变化。提出了一种新的分时段多模型组合预测方法。根据负荷组成和特征变化,将日96点负荷分为多个时间段,每个时段内采用多元线性回归、灰色预测、支持向量机和神经网络预测等子模型加权实现多模型组合预测。通过对华东某地市电网日负荷96点曲线的预测结果显示,该方法效果较好,日预测均方根误差在1.78%以内,能较好地满足实际电力系统的负荷预测要求。     

基于PCA与改进BP神经网络相结合的电网中长期负荷预测

本文在标准反向传播神经网络的基础上,提出一种结合主成分分析法和改进的误差反向传播神经网络的方法来对电网中长期的电力负荷进行预测。首先利用主成分分析法对电力负荷的影响因素进行特征提取,有效地降低数据样本的维度,消除数据的冗余和线性信息,保留主要成分作为模型的输入数据。然后在标准的神经网络的反向传播环节中引入动量项和陡度因子。两种方法的结合有效地解决了网络收敛速度慢和容易陷入局部最小值的问题。将此方法应用于济源市的中长期电力负荷预测,实验结果表明,基于主成分分析法与改进的反向传播神经网络相结合的方法比常用的标准的反向传播神经网络、基于多变量的时间序列网络及时间序列网络具有更高的计算效率和预测精度,证明提出的预测模型在电力负荷预测中是有效的。     

Forecasting and Prediction Applications in the Field of Power Engineering

Within the field of power engineering, forecasting and prediction techniques underpin a number of applications such as fault diagnosis, condition monitoring and planning. These applications can now be enhanced due to the improved forecasting and prediction capabilities offered through the use of artificial neural networks. This paper demonstrates the maturity of neural network based forecasting and prediction through four diverse case studies. In each case study the authors have developed diagnostic, monitoring or planning applications (within the power engineering field) using neural networks and industrial data. The engineering applications discussed in the paper are: condition monitoring and fault diagnosis applied to a power transformer; condition monitoring and fault diagnosis applied to an industrial gas turbine; electrical load forecasting; monitoring of the refuelling process within a nuclear power station. For each case study the data sources, data preparation, neural network methods and implementation of the resulting application is discussed. The paper will show that the forecasting and prediction techniques discussed offer significant engineering benefits in terms of enhanced decision support capabilities.     

ANNSTLF-a neural-network-based electric load forecasting system

A key component of the daily operation and planning activities of an electric utility is short-term load forecasting, i.e., the prediction of hourly loads (demand) for the next hour to several days out. The accuracy of such forecasts has significant economic impact for the utility. This paper describes a load forecasting system known as ANNSTLF (artificial neural-network short-term load forecaster) which has received wide acceptance by the electric utility industry and presently is being used by 32 utilities across the USA and Canada. ANNSTLF can consider the effect of temperature and relative humidity on the load. Besides its load forecasting engine, ANNSTLF contains forecasters that can generate the hourly temperature and relative humidity forecasts needed by the system. ANNSTLF is based on a multiple ANN strategy that captures various trends in the data. Both the first and the second generation of the load forecasting engine are discussed and compared. The building block of the forecasters is a multilayer perceptron trained with the error backpropagation learning rule. An adaptive scheme is employed to adjust the ANN weights during online forecasting. The forecasting models are site independent and only the number of hidden layer nodes of ANN's need to be adjusted for a new database. The results of testing the system on data from ten different utilities are reported.     

基于模块化回声状态神经网络光伏发电量预测

针对光伏发电的不确定性、间歇性给电力系统并网运行带来的安全问题,提出了一种基于模块化回声状态网络模型对发电量进行预测.首先利用模块化神经网络按季节建立预测子模型,再将子模型按相同日类型进行数据划分后,与平均气温一同作为样本,利用回声状态网络对子模型进行训练和发电量预测,最后集成输出结果.结果表明:此预测模型在日类型相同时预测误差较小,而在日类型不同时预测误差较大,但与ESN和BP预测模型相比均具有更高的预测精度和更快的预测速度.     

基于小波分析与神经网络的交通流短时预测方法

提出基于小波分析与神经网络的交通流短时预测方法，把多维输入进行小波分解降维，预测由多个子网络独立完成，有效解决了多维神经网络的映射学习容易产生“疆数灾”的问题．示例结果表明，该方法比典型的神经网络预测准确度高、误差小．     

Short‐term electric power load forecasting based on cosine radial basis function neural networks: An experimental evaluation

This article presents the results of a study aimed at the development of a system for short‐term electric power load forecasting. This was attempted by training feedforward neural networks (FFNNs) and cosine radial basis function (RBF) neural networks to predict future power demand based on past power load data and weather conditions. This study indicates that both neural network models exhibit comparable performance when tested on the training data but cosine RBF neural networks generalize better since they outperform considerably FFNNs when tested on the testing data. © 2005 Wiley Periodicals, Inc. Int J Int Syst 20: 591–605, 2005.     

A Hierarchical Self-Organizing Map Model in Short-Term Load Forecasting

This paper proposes a novel neural model to the problem of short-term load forecasting. The neural model is made up of two self-organizing map nets – one on top of the other. It has been successfully applied to domains in which the context information given by former events plays a primary role. The model was trained and assessed on load data extracted from a Brazilian electric utility. It was required to predict once every hour the electric load during the next 24 hours. The paper presents the results, and evaluates them.     

Big data solar power forecasting based on deep learning and multiple data sources

In this paper, we consider the task of predicting the electricity power generated by photovoltaic solar systems for the next day at half‐hourly intervals. We introduce DL, a deep learning approach based on feed‐forward neural networks for big data time series, which decomposes the forecasting problem into several sub‐problems. We conduct a comprehensive evaluation using 2 years of Australian solar data, evaluating accuracy and training time, and comparing the performance of DL with two other advanced methods based on neural networks and pattern sequence similarity. We investigate the use of multiple data sources (solar power and weather data for the previous days, and weather forecast for the next day) and also study the effect of different historical window sizes. The results show that DL produces competitive accuracy results and scales well, and is thus a highly suitable method for big data environments.     

基于进化神经网络的短期电网负荷预测算法

本文提出了一种基于进化神经网络的短期电网负荷预测算法。该算法使用了改进的人工蜂群算法与BP神经网络融合生成的进化神经网络,并且使用改进的人工蜂群算法对进化神经网络的偏置和权重进行优化。该算法将火电历史负荷数据作为输入,使用进化神经网络训练预测模型,预测未来一段时间内的电网负荷。首先获取历史负荷数据,然后将收集到的数据应用于进化神经网络模型训练。人工蜂群算法作为一种全局搜索算法,可以有效地探索模型参数空间,寻找最佳的模型参数组合以提升预测精度。为了验证所提出的负荷预测方法的有效性,本文使用了火电网负荷数据进行测试。实验结果表明,在短期电网负荷预测方面,本文提出的进化神经网络比传统方法预测结果更加准确可靠。     

基于交变粒子群BP网络的电力系统短期负荷预测

短期负荷预测是电力系统正常运行的关键环节,合理的发电计划依靠准确的负荷预测,因此提出交变粒子群算法来优化BP网络模型以预测电力短期负荷。针对 依靠先前的经验 来确定BP神经网络的权值缺少理论依据的问题,采用交变粒子算法优化BP神经网络权值,以减少通过神经网络预测模型求解电力短期负荷预测带来的误差。实验证明,经过优化的BP神经网络预测模型比传统的BP神经网络预测模型的误差更小,更加接近实际电力负荷。     

改进Pi-sigma神经网络及其算法在短期负荷预测中的应用

针对电力负荷的特点,综合考虑历史负荷、天气、日类型等因素的影响,将模糊逻辑和神经网络的长处融合在一起,构建了基于改进Pi-sigma神经网络及其算法的短期负荷预测模型,用于预测预报日的各小时负荷,其中在学习速率的选择、隶属度函数参数的更新等多处进行了改进,进一步减小了预测误差.地区电网的实际应用证明了该算法的有效性.     

基于RBF神经网络的短期负荷预测

短期电力负荷预测是电力系统运行调度中一项重要的内容,传统的电力负荷预测方法都是建立在线性假设基础之上,由于预测精度低,难以满足现在电力部门的要求。人工神经网络己被应用在电力负荷预测中,并取得了较为理想的结果。主要基于神经网络的负荷预测模型,通过MATLAB仿真实验平台,构建RBF神经网络模型,并用历史电力负荷数据进行训练,成功的进行了电力系统的短期负荷预测,预测结果误差较小,取得了令人满意的结果。     

模糊神经网络在电力短期负荷预测中的应用

提出用于电力短期负荷预测(SILF)的一种模糊神经网络(FNN)方法，该方法针对BP网络收敛速度慢、易导致局部极小值的缺点，将考虑气候、温度、星期类型等影响因素的模糊技术与快速二阶BP网络相结合，并以南方电网负荷预测为例，应用MATLAB蚀语言对系统进行仿真训练，测试结果表明，该方法具有较高的预测精度。