Price prediction of power transformer materials based on CEEMD and GRU

The rapid growth of the Chinese economy has fueled the expansion of power grids.Power transformers are key equipment in power grid projects,and their price changes have a significant impact on cost control.However,the prices of power transformer materials manifest as nonsmooth and nonlinear sequences.Hence,estimating the acquisition costs of power grid projects is difficult,hindering the normal operation of power engineering construction.To more accurately predict the price of power transformer materials,this study proposes a method based on complementary ensemble empirical mode decomposition(CEEMD)and gated recurrent unit(GRU)network.First,the CEEMD decomposed the price series into multiple intrinsic mode functions(IMFs).Multiple IMFs were clustered to obtain several aggregated sequences based on the sample entropy of each IMF.Then,an empirical wavelet transform(EWT)was applied to the aggregation sequence with a large sample entropy,and the multiple subsequences obtained from the decomposition were predicted by the GRU model.The GRU model was used to directly predict the aggregation sequences with a small sample entropy.In this study,we used authentic historical pricing data for power transformer materials to validate the proposed approach.The empirical findings demonstrated the efficacy of our method across both datasets,with mean absolute percentage errors(MAPEs)of less than 1%and 3%.This approach holds a significant reference value for future research in the field of power transformer material price prediction.

House Price, Consumption Power and Gap of Demographic Urbanization in China

This paper investigates the gap of demographic urbanization arising from the difference between rural residents who have migrated to cities and those who have acquired urban citizenship in the process of China's urbanization. The skyrocketing house prices and insufficient household consumption power are key factors to the widening gap, which had reached 18% in 2013. In order to explore this issue, by creating the basic model and the model with interaction term, this paper has analyzed the relationship among house prices, consumption power and gap of urbanization using the data of 31 provinces between 1999 and 2013 in China. Empirical result indicates that: there is a positive correlation between the house prices and the gap of China's demographic urbanization. However, such a correlation is restrained by these rural migrants who rent houses in cities. For an increase of house price by 1%, the gap of urbanization will widen by 1.05%. Although rising urban consumption power of rural residents has increased the ratio of migration, the lagged growth of consumption power has led to a widening gap of urbanization. Therefore, the only way to effectively reduce the gap of demographic urbanization is to increase the consumption power of migrant population and optimize consumption structure.

Impact of Electric Vehicle Charging on Power Load Based on TOU Price

Large-scale electric vehicle charging has a significant impact on power grid load, disorderly charging will increase power grid peak load. This article proposes an orderly charging mechanism based on TOU price. To build an orderly charging model by researching TOU price and user price reaction model. This article research the impact of electric vehicle charging on grid load by orderly charging model. With this model the grid’s peak and valley characteristics, the utilization of charging equipment, the economics of grid operation can all be improved.

Impacts of a Japan–South Korea power system interconnection on the competitiveness of electric power companies according to power exchange prices

In many regions,international power system interconnections provide economic,energy-security,environmental,and technical benefits.In contrast,such interconnections remain scarce in Northeast Asia.In 2016,after approving a joint memorandum of understanding between major electric power companies from China,Japan,South Korea,and Russia,related initiatives regained momentum in the region.Nevertheless,the corresponding developments in Japan remain limited,mainly owing to the lack of involvement of Japanese electric power companies.This study represents a pioneering attempt to provide an economic assessment based on power exchange prices of a power system interconnection between Japan and South Korea regarding the competitiveness of electric power companies in terms of competitive business segments and strategic consequences.We found that although the position of Japanese generators may slightly deteriorate,that of the supply segment would substantially improve,thus suggesting that more opportunities than threats are derived from the interconnection.This promising outcome may foster the adoption of an interconnection with South Korea considering the positive economic and business perspectives in Japan.Furthermore,realizing the interconnection may improve the energy security and air quality in the region.

Double Pressure on Power Grids——The demand for electricity is dropping while the electricity price is not adjusted properly

Since October 2008,China's social consumption of electricity had,for the first time,grown negatively compared to the same period of the previous year,and in November the negative growth range further expanded. The major pressure faced by the electricity industry has now turned from the contradiction between coal and electricity to electricity quantity. This is undoubtedly a true and new test to electricity enterprises which get used to high growth but are now suffering great losses. The reform of electricity system has already been in great difficulties and now is getting into a more serious situation. In order to help readers improve their knowledge and understanding of the current tough situation faced by the electricity industry and discuss how to alleviate and get through the difficulty resulted from the economic crisis "encountered once every one hundred years" by joint efforts of all parties concerned,a Seminar on Crisis and Countermeasures for Electricity Industry was held on November 20,2008. Here are some extracts from the speeches of four experts.

Goal and Progress of Power Tariff Reform——An interview with Liu Zhenqiu,Vice Director ofDepartment of Price,NDRC

● Power tariffreform has made many important and substantialprogresses in respect ofmarketization● The benchmark tariff is a revolutionary progress made in China's power tariff reform● Coal-electricity price linkage is a transitional approach which needs further improvement● The principle of T&D pricing is "cost plus profit," but it can also be based on pro rata control● China's electricity market should choose the mode of bilateral contracting combined withcentralized market● The direction of the power tariff reform is that electricity price shall be controlled mainly by the re-lationship between supply and demand in the

A Study on Renewable Power Pricing Mechanism and Price Incentive Policies in China

The basic framework of price policies for promoting renewable power de- velopment in China is introduced. The background, concept and implementation of price policies, focused on wind power, biomass power and solar power, are summarized in the article. The experiences and lessons of implementation of these price policies are analyzed. It is concluded that reasonable price policy is quite effective for promoting re- newable power development. According to the requirement of China's renewable power development, the suggestions for improving renewable power pricing mechanism and price incentive policies are proposed.

How to Realize Power Price Reduction in China?

In order to make power price truly reflect the cost of electric power and a reasonable profit without making the price unaffordable to the public, the government would have to adopt measures including tax reduction, surcharge reduction, debt relief and coal price reduction.

Primary Study of Power-Exchanging Trans- action Model Among Price-Varied Power Plants in Practical Conditions

At present, electricity price to grid of domestic power plants is priced by the national administration based on the policy of "one power plant with one electricity price to grid," which is difficult to realize real bidding for access to grid in practice in a short term. This paper presents one kind of power-exchanging transaction model among price-varied power plants, which will be beneficial to price-varied power plants without any loss of profits of them and guarantee state-owned assets profits in minimum loss with no promotion of average price limit by power plants. Under ideal conditions, the computation results showed the sufficiency and necessity of power-exchanging transaction and maximum similarity with the requirements of optimized resources disposition in economics. The presented model is shown to be full of practicability and has been used in some part of power market.

Research on Optimal Configuration of Energy Storage in Wind-Solar Microgrid Considering Real-Time Electricity Price

Capacity allocation and energy management strategies for energy storage are critical to the safety and economical operation of microgrids.In this paper,an improved energymanagement strategy based on real-time electricity price combined with state of charge is proposed to optimize the economic operation of wind and solar microgrids,and the optimal allocation of energy storage capacity is carried out by using this strategy.Firstly,the structure and model of microgrid are analyzed,and the outputmodel of wind power,photovoltaic and energy storage is established.Then,considering the interactive power cost between the microgrid and the main grid and the charge-discharge penalty cost of energy storage,an optimization objective function is established,and an improved energy management strategy is proposed on this basis.Finally,a physicalmodel is built inMATLAB/Simulink for simulation verification,and the energy management strategy is compared and analyzed on sunny and rainy days.The initial configuration cost function of energy storage is added to optimize the allocation of energy storage capacity.The simulation results show that the improved energy management strategy can make the battery charge-discharge response to real-time electricity price and state of charge better than the traditional strategy on sunny or rainy days,reduce the interactive power cost between the microgrid system and the power grid.After analyzing the change of energy storage power with cost,we obtain the best energy storage capacity and energy storage power.

基于主从博弈的多虚拟电厂动态定价与优化调度

在“双碳”背景下,分布式可再生能源以及储能、需求响应等灵活性资源快速发展,虚拟电厂通过控制技术将分布式资源高效整合,提高了分布式能源发电效益。随着社会资本进入电力市场,不同虚拟电厂将会属于不同的投资商,形成多主体博弈格局,根据投资商投资偏好,虚拟电厂将由不同灵活性的资源构成。为兼顾虚拟电厂运营商和虚拟电厂利益,文章构建了运营商和多虚拟电厂双层主从博弈模型,考虑上层定价与下层出力的相互影响,研究运营商动态价格制定和虚拟电厂优化运行调度问题。下层以各虚拟电厂运行成本最小为目标,分别建立含有电储能、需求响应和氢储能的多虚拟电厂优化调度模型;上层以运营商利润最大为目标,结合下层出力计划进行虚拟电厂购售电价动态制定。采用粒子群算法迭代求解博弈模型,通过算例分析,该模型能够兼顾多主体利益,有效提高运营商收益并降低虚拟电厂运行成本。

中国式现代化视角下中国铁矿石类大宗商品对外贸易定价权研究

改革开放以来中国经济发展迅速,逐渐步入工业化中后期阶段,对各类大宗商品的需求与日俱增。在国际市场,中国作为全球大宗商品重要的贸易国与消费国,缺乏对大宗商品定价权的影响力,受大宗商品国际价格波动影响较大,在国际大宗商品贸易中较为被动。基于国际铁矿石贸易市场的基本现状,以铁矿石为切入点,分析了当前中国在国际大宗商品的定价权,根据国内大宗商品进口贸易情况,探讨了在国际贸易中中国大宗商品定价权缺失的原因,并提出了相关对策建议。

考虑市场影响的风电厂与储能运营商联合调度策略研究

本文基于拥有风力发电厂与电力储能设备的电力运营商视角,考虑运营商参与电力交易会对市场电价产生影响的基础上,通过动态规划,以利润最大化为目标,研究其最优联合调度策略。研究表明:在考虑充放电效率以及运营成本时,存在三个最优参考点将储能设备中的可用库存空间分为四个区域,进而对应四个不同的决策活动:将风电和从市场上购买的电力全部存入储能系统;将部分风电存入储能系统并将剩余部分销售到市场;售出全部风电不向储能设备中存入电量;将所有的风电和储能系统中的部分电量销售至电力市场。运营商可根据当前时刻风力发电量和储能设备中的电量与最优参考点之间的大小关系,得到相应的最优电力调度策略及其交易量。此外,本文研究发现随着市场影响强度的增大,运营商的利润随之减小,因此运营商应在其市场影响强度与最优电力交易量之间做好权衡。本研究对运营商的电力调度具有重要的指导意义和实际应用价值。

四川省气电容量成本回收机制研究

四川省发展气电是实现“双碳”目标,提升电力调峰调频、确保安全稳定供电的重大举措。2022年四川省出台气电上网两部制电价政策指导意见,明确气电容量电价按一定合理收益回收固定投资成本,电量电价与气价实施联动调整。通过梳理国家及部分省份的气电两部制电价政策,调查分析四川气电的成本构成,研究对气电投资成本回收机制并测算容量电价,提出了容量电价测算原则、方法以及疏导路径的相关建议。研究结果表明:①因地制宜出台气电价格政策有利于推动气电产业健康可持续发展;②实施气电两部制电价有利于通过容量电价回收固定成本且取得合理收益,有利于促进四川气电产业有序健康可持续发展,并通过相对较低的电量电价实现与电力市场逐步接轨,增强市场竞争力;③容量电价按照“谁受益、谁承担”和“合理分摊、动态调整”原则进行疏导;④气电容量电价标准按资本金内部收益率8%对应取值,F机组容量电价标准可为28元/(kW·月),并且容量电费由该省内大工业、一般工商业用户疏导分摊。

国有大型油气企业新能源发电项目经济评价探讨

国有大型油气企业基于减排降碳和可持续健康发展考量,积极探索新能源发电业务,投资项目经济评价方法和参数,成为影响新能源发电业务投资决策和高质量发展的决定性因素。基于经济评价基本原理,根据新能源发电项目技术经济特征,构建新能源发电项目经济评价方法和参数体系。折现现金流法仍然是新能源发电项目经济评价的主要方法,内部收益率和平准化度电成本是衡量项目盈利能力的重要指标。不同类型新能源发电项目经济评价方法具有较高的一致性,但应在投资构成、成本费用估算、收入与税金估算等方面体现差异,重点在营业收入估算中体现项目真正价值。在规制性配置储能要求以及储能收益政策有待落实的情况下,新能源发电项目效益有待提高,建议现阶段适当降低投资回报要求,尤其是出于市场拓展和协同发展目的的战略性新能源发电项目。项目电价和有效利用小时数对新能源发电项目的影响至关重要,应视情况合理选取参数。风光气电融合项目应分业务估算成本。国有大型油气企业应积极开展宏观配套政策和商业模式创新研究,以支撑新能源发电业务的高质量发展。

Price-taker在两个电力市场中的交易决策 (二)发电商的策略

在对购电商两市场交易量优化分配问题研究的基础上,讨论了Price-taker发电商如何在考虑两市场电价风险的情况下进行交易电量的优化分配,以便在规避价格风险的同时追求尽可能大的收益。文中对Price-taker发电商的两市场交易量分配策略进行了建模和研究,给出了总交易量和各市场交易的优化解并为发电商如何选择风险因子提出了建议。文中给出了仿真算例。

考虑源网荷效益的峰谷电价与峰谷时段双层优化模型

用户响应行为测算需求解峰谷时段与峰谷电价之间的双线性项,目前仅考虑负荷曲线的数值大小对峰谷时段进行单独划分,分时电价实行效果受限。提出峰谷时段与峰谷电价的双层优化模型,考虑风电不确定性下的规划成本与发电成本,反映分时电价的实际经济效用;考虑用户响应的不确定性,保证分时电价实行后的源网荷效益在一定范围内变化;峰谷时段划分与峰谷电价设计均以系统成本最低为目标优化得到,充分考虑峰谷时段划分、峰谷电价设计和用户响应行为之间的交互机理。仿真结果表明,与单独划分峰谷时段的模型相比,所提模型能够制定更优、科学性更强的峰谷时段和峰谷电价,进一步降低系统总成本。

针对温控负载变化的虚拟电厂控制策略研究

温控负载是一种变化剧烈、波动频繁、高峰负荷比例较高的负载,对电网的安全产生了极大的影响。为了应对这一问题,系统的输出功率往往会超过90%负荷最大值的调峰限制。针对虚拟电厂(VPP)系统内的超限过程进行了研究,并提出了2种控制策略,以降低超限总电量或者利用超限电量的同时获取收益。在验证策略的控制效果时,选取了2种由温控负载引起的功率需求的典型变化。研究结果表明,温控负载引起的功率需求峰值的变化对策略具有重要影响。在安全模式下,超限比例与峰值的增加呈反比,而与平均功率的增加呈正比;在收益模式下,峰值变化会影响储能放电过程,平均功率变化则会影响储能充电过程。随着功率需求的增加,收益逐渐减小,收益范围为3.62万~3.25万元。

基于第三方服务的楼宇集群共享储能成本优化

分布式可再生能源发电设备在城市中日益普及,配置储能是应对其出力不确定性的有效措施。采用广义纳什议价理论提出了一种基于第三方服务的楼宇集群共享储能成本优化模型。以楼宇、储能运营商在主从博弈纳什均衡时的运行成本作为谈判破裂点,建立楼宇、储能运营商多主体纳什议价模型,并等效转化为系统运行成本最小子问题和虚拟储能议价子问题。在虚拟储能议价子问题中,针对一般纳什议价过程中各主体议价能力无差异的问题,采用年度充放电量衡量楼宇对共享储能系统的贡献,并作为议价能力参数参与协商制定虚拟储能容量租赁价格。算例结果表明:纳什议价机制下楼宇和储能运营商具有平等的议价权,可获得比主从博弈机制下更低的虚拟储能容量租赁价格,从而使楼宇运行成本下降,储能运营商收益提升,实现了共享储能系统经济效益的全局最优。基于充放电量构建的议价能力参数体现了楼宇对共享储能系统贡献的差异性,可提高楼宇参与共享储能的积极性,缩短储能运营商的静态投资回收期。