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.     

Implementation of an intelligent digital switchboard system

In this paper, an artificial neural network (NN) is used to improve a conventional electric switchboard. The NN used in this paper has two purposes. First, it is used to detect electrical sparks from damaged insulation of electric wire by decrepitude or line damage in indoor electric wire. Second, an autoregressive (AR) NN is used to predict the electrical load in a month so that the management of energy can be administered effectively. This ARNN is used for prediction and learning associated with an on-line process. The data to produce the initial weights of the NN for electrical load forecasting are obtained from the electrical load data of the previous year. The learning through the ARNN is achieved by an off-line process. Because the adaptation period of a NN can be considerably long when random initial weights are used, off-line learning is induced, thereby decreasing the prediction time. After learning, the NN weights are set to the initial values and the NN is implemented to predict the electrical load. It is confirmed that the method developer in this paper has better performance than the conventional one.     

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.     

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。     

A novel combined model based on hybrid optimization algorithm for electrical load forecasting

Accurate electrical load forecasting always plays a vital role in power system administration and energy dispatch, which are the foundation of the smooth operation of the national economy and people’s daily life. Thinking from this vision, many scholars have made great efforts to seek suitable optimization algorithms to improve the performance of existing forecasting algorithm. However, most of the studies ignore the inherent disadvantages of single optimization algorithm, which leads to sub-optimal forecasting performance. Therefore, a novel electric load forecasting system was successfully proposed in this paper by the combination of data preprocessing, hybrid optimization algorithms, and several single classical forecasting methods, which successfully overcomes the defects of single traditional forecasting models and achieves higher forecasting accuracy than that of single model optimization. Besides, the 30 min interval data of Queensland, Australia from March to April is used as illustrative examples to evaluate the performance of the developed model. The results of tests demonstrate that the proposed hybrid model can better approximate the actual value, and it can also be employed as a useful tool for smart grids dispatching planning.     

遗传优化支持向量机在电力负荷预测中的应用

研究电力负荷准确预测问题,电力负荷与影响因子之间呈现复杂非线性关系,传统预测方法无法刻画其变化规律,预测精度低。为提高电力负荷预测精度,提出一种采用遗传优化支持向量机的电力负荷预测模型。采用最小二乘支持向量机的非线性逼近能力去描述电力负荷与影响因子间的复杂非线性关系,并采用自适应遗传算法优化最小二乘支持向量机的参数。采用某省1990～2008年电力负荷数据仿真测试,结果表明,遗传优化支持向量机提高了电力负荷的预测精度,预测平均误差低于其它对比模型,电力负荷预测提供了一种新的研究思路和途径。     

基于级联网络的电力系统短期负荷预测

电力系统短期负荷预测对电力系统运行设计具有十分重要的意义。因此，在分析了电力负荷运行曲线的基础上，提出了一种基于级联模糊神经网络的预测模型。该模型采用基于神经网路理论的模糊模型参数辨识方法，很适合于复杂系统的模糊预测和控制。详细地对输入量的选择和学习算法进行了分析。实例表明，此方法具有町靠、鲁棒性好和快速等特点，优于神经网络电力负荷预报方法。     

基于气象数据可视化降维和多模加权组合的短期负荷预测

针对短期负荷预测中数据预处理的必要性和单一预测模型的局限性,提出了一种基于气象数据可视化降维和多模加权组合的短期负荷预测方法。该方法将可视化降维、模态分解降噪、单一预测模型和权重确定理论相结合,构建了气象数据降维、历史负荷分解、模态分量降噪和多模加权组合的短期负荷预测模型。通过设置3种对比实验环境,对某地区供电公司所提供的电力负荷和气象数据进行分析。预测结果及误差分析表明,所提短期负荷预测方法在保留高维气象因素本质特征结构的同时,能有效结合数据预处理方法及单一预测模型的特点,有效提升该地区电网负荷的预测精度。     

A hierarchical neural model with time windows in long-term electrical load forecasting

A novel hierarchical hybrid neural model to the problem of long-term electrical load forecasting is proposed in this paper. The neural model is made up of two self-organizing map nets: one on top of the other, and a single-layer perceptron. It has application into domains which require time series analysis. The model is compared to a multilayer perceptron. Both the hierarchical and the multilayer perceptron models are endowed with time windows in their input layers. They are trained and assessed on load data extracted from a North-American electric utility. The models are required to predict once every week the electric peak-load and mean-load for the next 2 years. The results are presented and evaluated in the paper.     

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。     

基于特征迁移学习的综合能源系统小样本日前电力负荷预测

基于历史数据和深度学习的负荷预测已广泛应用于以电能为中心的综合能源系统中以提高预测精度,然而,当区域中出现新用户时,其历史负荷数据往往极少,此时,深度学习难以适用.针对此,本文提出基于负荷特征提取和迁移学习的预测机制.首先,依据源域用户历史负荷数据,融合聚类算法和门控循环单元网络构建源域数据的特征提取和分类模型;然后,...     

A least squares support vector machine model optimized by moth-flame optimization algorithm for annual power load forecasting

Annual power load forecasting is essential for the planning, operation and maintenance of an electric power system, which can also mirror the economic development of a country to some extent. Accurate annual power load forecasting can provide valuable references for electric power system operators and economic managers. With the development of Energy Internet and further reformation of electric power market, power load forecasting has become a more difficult and challenging task. In this paper, a new hybrid annual power load forecasting model based on LSSVM (least squares support vector machine) and MFO (Moth-Flame Optimization algorithm) is proposed, which the parameters of LSSVM model are optimally determined by the latest nature-inspired metaheuristic algorithm MFO. Meanwhile, the rolling mechanism is also employed. The forecasting results of China’s annual electricity consumption indicate the proposed MFO-LSSVM model shows much better forecasting performance than single LSSVM, FOA-LSSVM (LSSVM optimized by fruit fly optimization), and PSO-LSSVM (LSSVM optimized by particle swarm optimization). MFO, as a new intelligence optimization algorithm, is attractive and promising. The LSSVM model optimized by MFO can significantly improve annual power load forecasting accuracy.     

Short-term electric power load forecasting using feedforward neural networks

Abstract: This paper presents the results of a study on short‐term electric power load forecasting based on feedforward neural networks. The study investigates the design components that are critical in power load forecasting, which include the selection of the inputs and outputs from the data, the formation of the training and the testing sets, and the performance of the neural network models trained to forecast power load for the next hour and the next day. The experiments are used to identify the combination of the most significant parameters that can be used to form the inputs of the neural networks in order to reduce the prediction error. The prediction error is also reduced by predicting the difference between the power load of the next hour (day) and that of the present hour (day). This is a promising alternative to the commonly used approach of predicting the actual power load. The potential of the proposed method is revealed by its comparison with two existing approaches that utilize neural networks for electric power load forecasting.     

基于随机森林的短期电量负荷精准预测方法

可再生能源并入电网后,电能供给量增加,短期电量负荷情况难以预测,无法制定准确的电能分配策略,由此,提出基于随机森林的短期电量负荷精准预测方法研究。深入分析短期电量负荷预测影响因素（气象、时间、电价与随机干扰因素）,选取适当的模型输入变量（历史电量负荷数据、温度数据与日类型）,结合随机森林算法构建短期电量负荷预测模型,并重复确定相似日的选取规则,采用粒子群优化算法寻找预测模型参数最佳值,将样本集输入至模型中,获得精准的短期电量负荷预测结果。实验数据显示:当输入变量数量达到一定值后,应用提出方法获得的短期电量负荷预测时延稳定在0.55s左右,短期电量负荷预测误差几乎为0,充分证实了提出方法应用性能较佳。     

基于双重注意力机制和GRU网络的短期负荷预测模型

电力负荷预测对电力系统的部署、规划和运行影响重大,但目前各输入特征对电网负荷情况影响的程度不稳定,且递归神经网络捕获负荷数据的长期记忆能力差,导致预测精度下降。提出一种基于双重注意力机制和GRU网络的预测新模型,利用特征注意力机制自主分析历史信息与输入特征间的关联关系,提取重要特征,并通过时序注意力机制自主选取GRU网络中关键时间点的历史信息,提升较长时间段预测效果的稳定性。在3个公开数据集上的实验结果表明,该模型在预测精度指标上表现良好,对比SVR、KPCA-ELM、DBN、GRU、Attention-GRU、CNN-LSTM、Attention-CNN-GRU模型预测精度分别提高了2.47、1.14、1.93、1.37、1.04、0.74、0.41个百分点。     

基于大数据的分布式光伏接入配电网影响分析与功率预测研究

为提高分布式光伏发电功率预测的精度,满足电网调度和规划的高精度要求,本文利用光伏运行、电能量采集、电网调度等业务系统的海量数据,利用大数据分析方法研究大量分布式光伏接入对配电网负荷特性的影响,并提出基于气象相似日和粒子群算法优化BP神经网络的光伏电站功率预测方法.通过分析光伏发电功率随天气类型、温度、光照强度等气象因素...     

基于改进自适应卡尔曼滤波的电力大负荷预测与计费研究

电力大负荷预测是电力公司进行高效电力系统规划和运行的重要基础;为了提高电力负荷预测精度进而更加有效地估计电力计量与计费,创新地提出了一种基于改进的自适应卡尔曼滤波(AKF)的电力大负荷计量计费预估方法;分析了电力负荷预测研究现状,针对传统卡尔曼滤波算法不足,引入自适应遗忘因子对卡尔曼滤波算法进行改进,建立数学模型、整定因子调整模型关键参数,得到电力大负荷数据的预测值,最终通过计量计费转换公式得用电量以及电费计量预估值;仿真结果表明：基于AEKF的电力大负荷计量预测方法的负荷预测结果与实际结果误差小于1.35%,电力计费预测结果与实际结果相对误差小于1.263%;应用实例证明：基于AEKF的电力大负荷计量计费预估方法,能够提高电力公司的调度效率12%,增加电费营收5.3%～12.2%。     

基于深度学习的智能楼宇微网负荷预测方法研究

楼宇微网是智能电网的重要组成部分,提高智能楼宇微网负荷预测精度,有助于对楼宇能效系统进行优化控制和调度规划。针对智能楼宇微网用电负荷数据的特点,提出了基于深度学习的智能楼宇微网短期负荷预测模型。首先用无监督的贪心算法对原始数据进行负荷数据的特征学习,完成对智能楼宇微网负荷数据的特征提取;然后挖掘智能楼宇微网负荷数据间的相互关系;最后用反向传播算法微调整个模型的参数。实验结果表明,提出的预测模型与传统预测模型相比具有更高的预测精度,且具有很好的可行性和有效性。     

A hybrid model of partial least squares and neural network for traffic incident detection

Development of a universal freeway incident detection algorithm is a task that remains unfulfilled and many promising approaches have been recently explored. The partial least squares (PLS) method and artificial neural network (NN) were found in previous studies to yield superior incident detection performance. In this article, a hybrid model which combines PLS and NN is developed to detect automatically traffic incident. A real traffic data set collected from motorways A12 in the Netherlands is presented to illustrate such an approach. Data cleansing has been introduced to preprocess traffic data sets to improve the data quality in order to increase the veracity and reliability of incident model. The detection performance is evaluated by the common criteria including detection rate, false alarm rate, mean time to detection, classification rate and the area under the curve (AUC) of the receiver operating characteristic. Computational results indicate that the hybrid approach is capable of increasing detection performance comparing to PLS, and simplifying the NN structure for incident detection. The hybrid model is a promising alternative to the usual PLS or NN for incident detection.     

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).