基于小脑模型关节控制器神经网络的短期电价预测

电价预测是电力市场决策的基础。文中介绍了采用小脑模型关节控制器(CMAC)神经网络建立预测提前1天不同时段的电力市场短期电价的预测模型。并以美国加州电力市场的数据作为计算实例，分别采用CMAC神经网络和反向传播算法(BP)神经网络进行短期电价预测。两种预测结果对比表明，CMAC神经网络具有所需训练样本少、输出稳定性好、计算速度快和预测精度高等优点，比较适用于短期电价预测。     

Day-ahead price forecasting in restructured power systems using artificial neural networks

Over the past 15 years most electricity supply companies around the world have been restructured from monopoly utilities to deregulated competitive electricity markets. Market participants in the restructured electricity markets find short-term electricity price forecasting (STPF) crucial in formulating their risk management strategies. They need to know future electricity prices as their profitability depends on them. This research project classifies and compares different techniques of electricity price forecasting in the literature and selects artificial neural networks (ANN) as a suitable method for price forecasting. To perform this task, market knowledge should be used to optimize the selection of input data for an electricity price forecasting tool. Then sensitivity analysis is used in this research to aid in the selection of the optimum inputs of the ANN and fuzzy c-mean (FCM) algorithm is used for daily load pattern clustering. Finally, ANN with a modified Levenberg–Marquardt (LM) learning algorithm are implemented for forecasting prices in Pennsylvania–New Jersey–Maryland (PJM) market. The forecasting results were compared with the previous works and showed that the results are reasonable and accurate.     

Investigating the effect of competitiveness power in estimating the average weighted price in electricity market

This paper aims at evaluating the impact of power extent on price in the electricity market. The competitiveness extent of electricity market during specific times in a day is considered to achieve this. Then, the effect of competitiveness extent on forecasting preciseness of daily power price is assessed. A price forecasting model based on multi-layer perception via back propagation with the Levenberg-Marquardt mechanism is used. Residual Supply Index (RSI) and other variables that affect prices are used as inputs to the model to evaluate market competitiveness. Results show that using market power indices as an input helps to increase forecasting accuracy. Thus, the competitiveness extent of market power in different daily time periods is a notable variable in price formation. Moreover, market players cannot ignore the explanatory power of market power in price forecasting. In this research, real data of electricity market from 2013 is used and the main source of data is the Grid Management Company in Iran.     

电价的混沌特性分析及其预测模型研究

在电力市场环境下,电价取决于众多因素的共同作用,它的演化过程呈十分复杂的不规则运动.为了揭示这种貌似随机的演化过程的内在规律,作者首先借助混沌理论,对电价的混沌特性进行了验证.在由电价单变量时间序列重构的相空间上,提取了吸引子的分形维数和Lyapunov指数,表明电价具有混沌特性;并且通过替代数据检验法进一步验证了电价的这种混沌行为,从而为借助混沌理论来进行电价的短期预测提供了依据.然后,采用电价及其相关因素构成的多变量时间序列重构了更为准确的相空间,通过跟踪相空间中相邻相点的演化趋势,建立起基于递归神经网络的全局和局域电价预测模型,并对New England市场的电价进行了成功的预测.     

电力市场短期边际电价的分时重构混沌相空间预测

为了实现高精度的电力市场短期边际电价预测,该文对市场边际电价时间序列数据分时段聚类进行了相空间重构,并分别计算分形维数和提取最大Lyapunov指数,经分析得出了边际电价分时序列数据的演化具有混沌特征,由此提出了短期边际电价的分时重构混沌相空间预测算法,相比目前通常采用的单一时间序列混沌预测算法,该算法具有相空间嵌入维数少和模型参数配置灵活的特点,通过电力市场短期边际电价预测实例验证,结果表明该算法比单一时序混沌预测算法在预测精度上有显著提高.     

基于小波包分解和长短期记忆网络的短期电价预测

在电力市场环境下,精准的短期电价预测可以保障电网优化调度和安全稳定运行,但实时电价具有非平稳性和非线性的特点,加大了预测难度。针对这一问题,提出了一种基于小波包分解（WPD）和长短期记忆（LSTM）网络的短期实时电价预测方法。将实时电价序列分解,得到最高频细节部分和低频趋势部分,剔除波动性高、无效信息多的高频细节部分,再采用LSTM网络对有效信息最多、更能体现电价序列的趋势部分进行实时电价预测。使用所提方法对美国PJM市场某地区实时电价数据进行预测实验,结果表明所提方法相比随机森林、BP神经网络、支持向量机电价预测方和传统的LSTM网络电价预测方法具有更高预测精度。     

短期电价预测综述

准确的短期电价预测可为市场参与者的竞价策略提供指导,从而减少参与者的竞价风险,为其带来稳定的收益,因此短期电价预测已成为电力市场中的研究热点。结合1997年以来的相关文献对短期电价预测进行了综述。在分析电价基本特点和电价影响因素的基础上,重点对时间序列法和神经网络法这2种常用的电价预测方法进行了评述,探讨了各方法可能的进一步研究方向。最后对电价影响因素选择、数据预处理和电价预测工具的选择这3个电价预测中的重要问题进行了讨论,并对短期电价预测的研究工作提出了一些建议。     

The effect of wind generation and weekday on Spanish electricity spot price forecasting

This paper empirically compares the predictive accuracy of a set of methods for day-ahead spot price forecasting in the Spanish electricity market. The methods come from time series analysis and artificial intelligence disciplines, and include univariate, multivariate, linear and nonlinear. Within the univariate methods, the double seasonal ARIMA and the recently proposed exponential smoothing for double seasonality are compared and used as benchmarks. They allow us to quantify the improvement on price forecasting when including explanatory variables or using more complex models. Dynamic regression models including the electricity load forecast are then considered. Their good performance in price forecasting has been pointed out by many authors. However, we find evidences of their predictive accuracy can be significantly outperformed by accounting the wind generation forecast provided by the System Operator. Moreover, these forecasts can be even more accurate if changes of price's behavior according with the day of the week are taken into account by means of periodic models. The last of the tested methods are feed-forward neural networks used as multivariate nonlinear regression methods with universal function approximation capabilities. The influence of the wind generation forecast on price prediction is also proved with this approach. Detailed out-of-sample results of the tested methods are given.     

基于R/S分析法的电价预测模型

在自由竞争的电力市场中,准确的电价预测对于电力市场所有参与者具有重要意义。针对电价突变性的特征给电价预测结果带来误差的问题,本文提出了一种基于R/S分析法的BP神经网络电价预测模型。运用R/S分析法对电价序列之间的关联性和相似性进行修正,并采用BP神经网络模型对电价进行预测。通过实验,验证了用R/S分析法修正后的数据进行电价预测模型具有更高的精确性。     

Mid-term electricity market clearing price forecasting: A hybrid LSSVM and ARMAX approach

A hybrid mid-term electricity market clearing price (MCP) forecasting model combining both least squares support vector machine (LSSVM) and auto-regressive moving average with external input (ARMAX) modules is presented in this paper. Mid-term electricity MCP forecasting has become essential for resources reallocation, maintenance scheduling, bilateral contracting, budgeting and planning purposes. Currently, there are many techniques available for short-term electricity market clearing price (MCP) forecasting, but very little has been done in the area of mid-term electricity MCP forecasting. PJM interconnection data have been utilized to illustrate the proposed model with numerical examples. The proposed hybrid model showed improved forecasting accuracy compared to a forecasting model using a single LSSVM.     

基于趋势指标与长短时记忆网络的电力市场日前电价预测

为提高电力市场日前电价的预测精度,提出一种基于趋势指标与长短时记忆网络（LSTM）的日前电价预测模型。首先,计算日前电价的随机指标（KDJ）与异同移动平均线指标（MACD）,挖掘电价的内在规律信息;然后,将计算出的趋势指标与电价信息输入LSTM,对电力市场日前电价进行预测;最后,利用电力市场日前电价数据进行验证。算例分析表明该模型相比反向传播神经网络（BPNN）、LSTM和门控循环单元网络（GRU）等模型预测精度更高。     

基于回声状态网络的电力市场电价预测

传统的神经网络算法在电价变化剧烈的情况下,精度较低并且所耗费的时间较长,难以满足电力市场发展的需求。为解决该问题,提出了一种基于回声状态网络(ESN)的短期电价预测方法。所提方法介绍了基于回声状态网络的预测原理,提出了电力市场短期电价的预测机制,包括参数选取、采样数据预处理和ESN训练及预测过程;并分别采用回声状态网络和反向传播算法(BP)神经网络进行短期电价预测。经过仿真验证,所提出的基于回声状态网络的电价预测具有较好的准确率和可行性。     

基于模糊聚类和关节控制器神经网络的边际电价预测

应用基于模糊聚类和关节控制器神经网络的边际电价预测方法,精确预测边际电价,并有效克服BP等算法中负荷峰谷时段出现的预测误差大、结果不稳定的现象.通过计算实例进行边际电价预测,预测结果表明:方法输出稳定性好、计算速度快、预测精度较高.     

基于最大信息系数相关性分析和改进多层级门控LSTM的短期电价预测方法

为准确预测电力市场中的短期电价,将最大信息系数(maximal information coefficient,MIC)相关性分析与改进多层级门控长短期记忆网络(multi-hierachy gated long shortterm memory,MHG-LSTM)相结合,提出一种新型短期电价预测方法。该方法首先对备选序列与预测电价序列做MIC相关性分析,在此基础上筛选备选序列并经小波变换合成神经网络输入序列,有效增加了输入中与预测电价相关的信息密度;其次,对传统LSTM进行创新性改进,提出用两级遗忘门和输入门替换传统的一级门控机构的MHG-LSTM模型,提高了神经网络选择和提取高频电价序列特征的能力。在PJM市场日前电价数据集上对所提方法进行仿真实验,实验结果表明,该方法的预测误差仅为4.506%,相比已有预测方法有效提升了短期电价的预测精度,且具有很强的普适性,可应用于电力市场短期电价预测,为市场参与者和监管机构提供有力决策依据。     

基于相似搜索和RBF神经网络的短期电价预测

为了提高电价预测的准确性,提出一种基于相似搜索和RBF神经网络的短期电价预测的方法。采用相似搜索原理来生成神经网络的训练集和输入矩阵,并运用MATLAB7.0中的神经网络工具来实现该模型。采用澳大利亚维多利亚电力市场2002年1月1日至3月17日共75天数据进行了实验分析,对3月11日～17日的各时段电价进行了预测,通过比较验证了本文方法的有效性。     

模糊神经网络在电力系统边际电价预测中的应用

文章针对短期电力系统边际电价预测研究和应用中存在的用多元回归等传统方法建模困难、用ANN方法学习速度慢和易陷入局部极小点等问题,利用模糊神经网络具有接受和处理模糊数据、自适应地以任意精度逼近映射函数、不要求明确的数学描述等优点,建立了基于模糊神经网络的系统边际电价预测模型.通过具体实例测算及现场运用,证明了该方法为提高电力市场中边际电价预测精度、制定和实施科学合理的发电企业报价策略提供了可靠的支持.     

Mixed price and load forecasting of electricity markets by a new iterative prediction method

Load and price forecasting are the two key issues for the participants of current electricity markets. However, load and price of electricity markets have complex characteristics such as nonlinearity, non-stationarity and multiple seasonality, to name a few (usually, more volatility is seen in the behavior of electricity price signal). For these reasons, much research has been devoted to load and price forecast, especially in the recent years. However, previous research works in the area separately predict load and price signals. In this paper, a mixed model for load and price forecasting is presented, which can consider interactions of these two forecast processes. The mixed model is based on an iterative neural network based prediction technique. It is shown that the proposed model can present lower forecast errors for both load and price compared with the previous separate frameworks. Another advantage of the mixed model is that all required forecast features (from load or price) are predicted within the model without assuming known values for these features. So, the proposed model can better be adapted to real conditions of an electricity market. The forecast accuracy of the proposed mixed method is evaluated by means of real data from the New York and Spanish electricity markets. The method is also compared with some of the most recent load and price forecast techniques.     

Mid-term electricity market clearing price forecasting utilizing hybrid support vector machine and auto-regressive moving average with external input

Currently, there are many techniques available for short-term electricity market clearing price (MCP) forecasting, but very little has been done in the area of mid-term electricity MCP forecasting. Mid-term electricity MCP forecasting has become essential for resources reallocation, maintenance scheduling, bilateral contracting, budgeting and planning purposes. A hybrid mid-term electricity MCP forecasting model combining both support vector machine (SVM) and auto-regressive moving average with external input (ARMAX) modules is presented in this paper. The proposed hybrid model showed improved forecasting accuracy compared to forecasting models using a single SVM, a single least squares support vector machine (LSSVM) and hybrid LSSVM-ARMAX. PJM interconnection data have been utilized to illustrate the proposed model with numerical examples.     

Price forecasting and validation in the Spanish electricity market using forecasts as input data

The electricity sector has been subjected to major changes in the last few years. Previously, there existed a regulated system where electric companies could know beforehand the amount of energy each generator would produce, hence basing their largely operational strategy on cost minimization in order to increase their profits. In Spain, from 1988 till 1997, electricity prices were established by the ‘Marco Legal Estable’ – Stable Legal Framework –, where the Ministry of Industry and Energy acknowledged the existence of certain generation costs related to each type of technology. It was an industrial sector with no actual competition and therefore, with very few controllable risks. In the aftermath of the electricity market liberalization competition and uncertainty arose. Electricity spot prices became highly volatile due to the specific characteristics of electricity as a commodity. Long-term contracts allowed for hedge funds to act against price fluctuation in the electricity market. As a consequence, developing an accurate electricity price forecasting model is an extremely difficult task for electricity market agents. This work aims to propose a methodology to improve the limitations of those methodologies just using historical data to forecast electricity prices. In this manner, and in order to gain access to more recent data, instead of using natural gas prices and electricity load historical data, a regression model to forecast the evolution of natural gas prices, and a model based on artificial neural networks (ANN) to forecast electricity loads, are proposed. The results of these models are used as input for an electricity price forecast model. Finally, and to demonstrate the effectiveness of the proposed methodology, several study cases applied to the Spanish market, using real price data, are presented.     

基于Attention-GRU的短期电价预测

通过分析得出电价与负荷具有相关性,因此在电价预测模型中需要考虑实时负荷的影响。在此基础上针对前馈神经网络不能处理时序数据的缺陷与LSTM神经网络预测速度慢的问题,提出了一种基于Attention-GRU (Attention gated recurrent unit, Attention-GRU)的实时负荷条件下短期电价预测模型。该模型充分利用电价的时序特性,并采用Attention机制突出了对电价预测起关键性作用的输入特征。以美国PJM电力市场实时数据为例进行分析,通过与其他几种预测模型相比,验证了该方法具有更高的预测精度;与LSTM神经网络相比具有更快的预测速度。