AP1000核电机组与抽水蓄能电站联合运行研究

随着核电机组容量的不断增大以及核电机组发电量占总发电量的比例不断增加,后续新建的核电机组必将会参与电网调峰,本文详细解析了AP1000核电机组负荷调节方式和特点,同时根据所选分析核电机组所在地区的地址条件,结合当地抽水蓄能电站的设计规划情况提出了核电机组直接参与电网日负荷调峰的运行模式。结合抽水蓄能的运行特性,比较分析了核电与抽水蓄能机组联合的调峰运行模式。AP1000核电机组具有良好的调峰能力,在投运负荷跟踪模式时可按照"12-3-6-3"的出力方式参与电网日负荷调峰,但其调峰的深度和速度受到安全性及经济性的限制。将抽水蓄能机组与核电机组联合运行,可满足电网调峰的要求,并保证核电机组带基本负荷稳定运行。     

1000MW超超临界火电机组深度调峰研究

随着国家越来越重视可再生能源的开发与利用,特别是风电、水电的飞速发展,电网负荷结构发生了较大的变化,电网在运行中负荷差明显增大。这就导致大型火力发电机组的深度调峰次数越来越多,调峰压力越来越大。火电企业为了在竞争日益激烈的发电市场获取更多市场份额,必须满足电网规定的深度调峰要求,提高机组的调峰能力,满足电网安全调度要求与正常运行的能力。本文从实际出发,针对百万超超临界火力发电机组的深度调峰问题,进行了深入的分析研究,并给出了简要的解决方案,为同类型机组的深度调峰工作提供了一定的借鉴意义。     

蒙东地区新能源发电特性与电网调峰需求研究

基于蒙东地区2018年风电和光伏历史数据,定量分析二者在月度、日间、日间峰谷时段、晚高峰爬坡时段的波动性以及对电网调峰的影响;分析不同季节保证出力率及其差异性;以系统达到平衡后火电机组的负荷率分布作为指标,计算分析了蒙东电网2025年对火电的峰谷调峰需求和晚高峰爬坡调峰需求。相关结论可为电网规划运行和火电灵活性改造提供参考依据。     

秦山CP-300机组参与电网调峰的分析与探讨

随着浙江电网负荷长期的连续增长,用电的峰谷差也逐步加大,另外随着我国核电的大发展,浙江省内将陆续有多台百万机组投入商运。由于环保方面的问题和核电在电网中的比重逐年增加,造成了很多常规火电厂的停运。而这又最终导致电网峰谷之间的缺口高达2000至3000兆瓦,同时还一定程度上造成电网调压、调频等方面的问题。理论上反应堆都具有一定的负荷跟踪能力以满足电网用电需求,但实际运行中,由于核电的特殊性,它的负荷跟踪能力会受到核安全等方面的一系列限制,所以需要做好权衡利弊。若CP-300机组参与调峰,本文从稳态和瞬态工况,对其安全性的影响进行分析,另外还介绍了几种可能用于CP-300核电机组参与电网调峰的运行方式。     

区域采用弃风电量供热

可靠运行灵活的风电弃风电量蓄热供热技术,不仅可以利用白白浪费掉的清洁能源,使电网、风电场都能获得额外经济效益,也是风电走出风机闲置和"弃风"尴尬境地的绝佳途径,能够有效解决电网外送困难和就地消纳能力不强问题,大大提高电网消纳风电和调峰能力。各项指标均符合和满足国家现行规定的要求,而且有比较乐观的供热市场前景。项目的实施,必将对风电发展产生推动作用。     

送端电网调控运行管理体系建设

在目前的送端电网调控运行当中,依然大量存在有火电机组调峰难度大,设备远程操控比例低,能源调度管理不规范,调控技术建设不先进等多方面的问题。对此,本文通过对上述送端电网调控运行管理问题的分析,进一步就提出了关于加强送端电网调度运行管理体系建设的一些具体策略。     

北京某办公楼冰蓄冷空调系统控制策略分析

从节能及碳排放的角度分析了北京市某办公楼冰蓄冷空调系统的控制策略。比较了无蓄冷、冰蓄冷承担基础负荷+基载主机调峰、基载主机承担基础负荷+冰蓄冷调峰3种运行模式。结果表明:冰蓄冷承担基础负荷+基载主机调峰的方式可实现运行成本的最大节约,但碳排放量会超出限制要求;基载主机承担基础负荷+冰蓄冷调峰的方式经济效益显著,且碳排放量可满足限制要求。     

西北电网跨省峰谷互济交易首次实现市场化

<正>西北电网东西部潮流交换频繁,因此系统运行互补性强。东部的陕西电网峰谷差大,低谷时段调整困难,有低谷送出需求;西部的青海光伏发电比重大,电网峰谷差小,高峰时段出力受限,有高峰送出需求;中部的甘肃新能源装机多,风电出力的波动性、间歇性增加了省间送受电的需求。近年来随着新能源装机迅猛增加,系统运行调峰能力不足的矛盾日益凸显,一方面新能源因缺少相应的大范围消纳机制,弃风弃光严重,另一方面省间调峰资源长周期无序使用,矛盾比较突出。     

2×660 MW机组接入区域电网系统安全稳定分析及对策研究

近年来随着国内外越来越多区域电网的运行和发展,受国家宏观政策导向以及追求高经济效益等因素影响,660 MW机组接入区域电网越发普遍,然而大机组的接入易形成"大机大负荷小网",往往会引发一系列运行和稳定问题,区域电网的稳定控制受到了严峻的挑战。结合220kV石河子电网的实例,通过时域仿真计算研究660 MW机组投运对区域电网潮流分布、短路电流、暂态稳定等方面的影响;提出了机组投运后区域电网安全稳定控制优化方案及运行方式调整指导建议,有效提高了区域电网安全稳定运行水平,为石河子电网的调度、运行和控制提供了有效的指导建议,同时对其他区域电网的运行控制具有较强的实际借鉴和参考价值。     

利用系统热惯性的热电联产电力调峰

分析了我国电力行业现阶段存在的问题,提出利用热网和建筑物的热惯性实施热电联产电力调峰的运行模式,对其可行性进行了探讨.利用热网和建筑物的热惯性实施的热电联产电力调峰运行模式既能使热电系统参与电力调峰,又能保证供热质量,是解决电力负荷峰谷差的良好途径.     

Decrease in CO2 emission per capita as a result of the reduction in power grid losses in Iran

ABSTRACT

In power grids, a significant amount of the generated power in power plants is wasted in the grid between power plants and consumers. The amount depends on different factors. With regard to the vital role of electricity in economic and social development alongside with high investment costs in electricity generation, transmission and distribution, practical solutions for decreasing grid losses and enhancing the efficiency of existing facilities are crucial. Due to the global environmental situation and significant effects of energy consumption on the environment, the general trend is towards the deployment of methods which are more efficient and less fuel consuming. In addition, more implementation of monitoring and controlling equipment and instalment of more efficient equipment in electricity transmission and distribution sectors reveal the effort towards the reduction of pollutants. These facts reveal the importance of this issue amongst authorities in the power industry. In this research through the assessment of power grid losses and studying different types of power plants in Iran, the amount of electricity generation and grid loss are studied. In addition, the impact of different power plants on the amount of environmental pollutants especially CO₂ is presented. Also, some solutions to reduce CO₂ emission are provided.     

Operational concerns and solutions in smart electricity distribution systems

Interfacing high penetration of Renewable Energy Sources (RES) with energy storage and microgrid control systems is an essential feature of future distribution grids for optimal utilization and management of Distributed Energy Resources (DERs). This feature allows distributed system operators to follow the right path to transform their traditional grids into smart grids. With the continued expansion of DERs, the current distribution grid is moving toward a carbon-free electricity system and greener energy-transportation applications. However, there are some practical concerns as well as technical and operational challenges in an interconnected power network. Therefore, this paper reviews the most prominent issues associated with smart grid, such as large-scale distributed generation integration, energy storage, energy trading, operational planning, service reliability, and cyber resiliency, in light of recent technological advancements. Through reviewing several emerging technologies, this study shows the necessary methodologies for establishing smart energy distribution. Finally, this study highlights future research prospects for a fully functional smart grid system.     

Seismic performance assessment of electric power systems subjected to spatially correlated earthquake excitations

Electric power systems play a critical role in assuring modern society’s functionalities. Earthquakes are one of the most destructive natural hazards that affect the serviceability of electricity transmission systems. The earthquake excitations applied to each component of a power system (e.g. plants, substations and transmission lines) are spatially correlated by nature due to common causes. Yet, limited attention has been paid to the impact of this spatial correlation on the power grid seismic performance. This article presents an approach for estimating the seismic performance of large-scale electric power systems subjected to spatially correlated earthquake ground motions. The network flow theory is used to model the power flow allocation over the grid components, and a stochastic ground motion model is employed to represent the spatial characteristics of earthquake excitations. The proposed method is illustrated through the seismic performance assessment of the national power grid of Italy. The overall vulnerability is measured and evaluated through a proposed metric, and the critical components of the grid system are identified. The impact of spatial correlation of earthquake ground motion on the grid system’s post-hazard performance is also investigated.     

Bearing force mobilisation in pull-out tests on geogrids

This paper presents a study on the mobilisation of bearing forces in geogrids subjected to pull-out solicitation. A theoretical model incorporating the effects of interference between grid bearing members on grid pull-out behaviour is presented and used for the interpretation of the results of large-scale pull-out tests on grids with varying geometrical and mechanical properties. The results obtained in this study show the influence of parameters such as free reinforcement length, test speed and interference between members on the pull-out response of geogrids. It is also shown that the load–displacement curve obtained in pull-out tests is not sufficient for an accurate investigation of soil–grid interaction and bearing force degradation mechanisms must be incorporated in the analysis of grid pull-out response if accurate predictions of pull-out strength and grid deformations are to be made.     

电网建设创新探索

为了满足国民经济的高速发展,近年来,基础设施建设投入在成倍增长,电网建设作为基础设施的重要组成部分,投责也在逐年加码,特别是”十二五”期间,将成几何级数增长,达到历史的顶峰,如此大规模的投入,新老问题扎堆,必须转变观念,勇于探索实践,创新思路来适应电网建设的大潮,实现电网建设跨越式的发展.     

State-of-the-art research on micro grid stability: a review

The usage of renewable energy resources (RES) in energy is receiving great attention as a solution to the problem of a shortfall in electrical energy. Application of RES in a generation system is done with diverse outlines, amongst others in a micro grid system. Employment of micro grid systems offers numerous benefits both for the consumer as well as for the utility provider. Voluminous micro grid expansions are carried out in more than a few countries, because it offers healthier power quality and furthermore it is ecologically friendly. Even though its adoption is growing steadily, there are still several hurdles to proficiently design, regulate, and operate micro grids when linked to the grid, and as well when in the islanded mode, and wide-ranging investigation activities are on-going to confront the issues. It is essential to consider across-the-board opinions of the micro grid amalgamation in a power system network. This paper presents a review of issues in relation to micro grid stability and offers an account of study in areas related to micro grids.     

Evaluating the ancillary services market for large-scale renewable energy integration in China's northeastern power grid

The installed renewable energy capacity in China is the largest in the world. However, the curtailment of renewable energy remains problematic. To alleviate this problem, a pilot for integrating the ancillary service market for renewable energy in China's northeastern power grid began in 2017. Before this time, a compensatory ancillary service cost mechanism was implemented, in which thermal plants not providing ancillary service paid the costs of the thermal plants providing ancillary service under government supervision. The pilot ancillary service market allowed thermal plants providing ancillary service to make independent quotes. Renewable energy plants were included in those paying the ancillary service costs. We examine the effects of the ancillary service market in the context of large-scale renewable energy integration. The results show that this market has given rise to competing interests between renewable energy and thermal plants. Therefore, measures must be taken to improve the ancillary service market, including eliminating the ancillary service bidding limits, establishing a renewable auction mechanism, and transforming the spot market.     

Heat supply to low-energy buildings in district heating areas: Analyses of CO2 emissions and electricity supply security

In several housing development projects in Norway the requirements related to the mandatory connection to district heating plants have shown to be a barrier for building low-energy residential buildings. The developers have considered the costs related to both low-energy measures and a space heating system that can utilize district heat to be too high to give the project acceptable profitability. In these projects the developers wanted to use a cheaper electric space heating system. Based on models representative for the range of the Norwegian district heating plants, calculations show that the CO₂ emissions related to heating in residential buildings with an energy standard in accordance with the new building regulations and that are connected to the district heating grid, are lower than for similar buildings with a low-energy standard and with heating based on electricity. However, in a long term perspective the differences are marginal when considering the national annual CO₂ emissions. Similarly, increased peak power demand due to electricity-based heating may also be regarded as marginal when compared to the present maximum peak power capacity in Norway.     

Analysis of the plug-in hybrid electric vehicle for the smart grid of Canada

The conventional electricity grids, which are supposed to supply the electricity to the plug-in hybrid electric vehicles (PHEVs), need to adapt to overcome the problems of reliability, security, economics and environmental concerns. Accordingly, electric utilities in several countries are exploring the possibilities of implementing more robust interactive smart grids. This article analyses salient features of a smart grid in the Canadian perspective, and discusses PHEV and its role in the future smart grid. A simulation tool has been used to assess the impacts of charging of PHEV on the future electricity grid of Canada under different penetration rates. The article indicates the associated environmental benefits of PHEV.     

球形吸附剂颗粒扩散方程的数值求解

对于速率控制的变压吸附过程而言,吸附剂颗粒上的扩散方程求解十分关键.采用有限差分法数值求解扩散方程,分别利用等距网格和等体积网格划分计算区域.结果表明,当网格节点数较少时,等体积网格比等距网格具有更高的计算精度.当球形计算区域网格节点足够密时,节点在计算区域的分布对计算结果影响不大,从而等距网格和等体积网格都可以达到较高的计算精度.