Carbon Emission Factors Prediction of Power Grid by Using Graph Attention Network

Advanced carbon emission factors of a power grid can provide users with effective carbon reduction advice,which is of immense importance in mobilizing the entire society to reduce carbon emissions.The method of calculating node carbon emission factors based on the carbon emissions flow theory requires real-time parameters of a power grid.Therefore,it cannot provide carbon factor information beforehand.To address this issue,a prediction model based on the graph attention network is proposed.The model uses a graph structure that is suitable for the topology of the power grid and designs a supervised network using the loads of the grid nodes and the corresponding carbon factor data.The network extracts features and transmits information more suitable for the power system and can flexibly adjust the equivalent topology,thereby increasing the diversity of the structure.Its input and output data are simple,without the power grid parameters.We demonstrated its effect by testing IEEE-39 bus and IEEE-118 bus systems with average error rates of 2.46%and 2.51%.

Multi-Criteria Decision-Making for Power Grid Construction Project Investment Ranking Based on the Prospect Theory Improved by Rewarding Good and Punishing Bad Linear Transformation

Using the improved prospect theory with the linear transformations of rewarding good and punishing bad(RGPBIT),a new investment ranking model for power grid construction projects(PGCPs)is proposed.Given the uncertainty of each index value under the market environment,fuzzy numbers are used to describe qualitative indicators and interval numbers are used to describe quantitative ones.Taking into account decision-maker’s subjective risk attitudes,a multi-criteria decision-making(MCDM)method based on improved prospect theory is proposed.First,the[−1,1]RGPBIT operator is proposed to normalize the original data,to obtain the best andworst schemes of PGCPs.Furthermore,the correlation coefficients between interval/fuzzy numbers and the best/worst schemes are defined and introduced to the prospect theory to improve its value function and loss function,and the positive and negative prospect value matrices of the project are obtained.Then,the optimization model with the maximum comprehensive prospect value is constructed,the optimal attribute weight is determined,and the PGCPs are ranked accordingly.Taking four PGCPs of the IEEERTS-79 node system as examples,an illustration of the feasibility and effectiveness of the proposed method is provided.

Large-Scale Distributed Photovoltaic Power Dispatching and Operation Management Review

Distributed photovoltaic power (PV) is the main development model of distributed generation. It is necessary to research on dispatching and operation management with large-scale distributed PV connected. This paper analyzes development status, technical requirement and dispatching and operation management situation of distributed PV in Germany and China. Then introduce the preparation of distributed PV dispatching and operation management criterion. Through summarizing the experiences and lessons of large-scale distributed PV development in Germany, it gives advice to the development of distributed PV dispatching and operation management in China.

Research on Security Assessment Index System for Operating Reserve in Large Interconnected Power Grid

Optimization and placement of spinning reserve is an important issue in power system planning and operation. Systematic way for security assessment of operating reserve needs to study. A security assessment index system for operating reserve in large interconnected power grids is presented in this paper. Firstly, classification and determination methods of operating reserve at home and abroad are investigated, and operating reserve is divided into transient state operating reserve and quasi-steady state operating reserve from the view of security assessment. Secondly, assessment indexes and optimization methods for transient state operating reserve are studied. Thirdly, optimization model, deterministic and probabilistic optimization methods for quasi-steady state operating reserve are explored. Finally, some principles for determination of operating reserve are suggested, and a security assessment index system is put forward. The proposed index system, considering both transient and quasi-steady state, both deterministic and probabilistic methods, provides a systematic way to assessment and arrangement of operating reserve.

Fundamental Research on Enhancing Operation Reliability for Large-Scale Interconnected Power Grids——An interview with Zhou Xiaoxin, chief scientist of "973 Program"

At the end of last year, the editors from Power and Electrical Engineers interviewed Zhou Xiaoxin on "Fundamental Research on Enhancing Operation Reliability for Large-Scale Interconnected Power Grids", a project of "973 Program". Mr. Zhou, the chief engineer of China Electric Power Research Institute(CEPRI) and an academician of Chinese Academy of Sciences, is the chief scientist in charge of this research project.

Regulating cost for renewable energy integration in power grids

To address the issue of climate change caused by the use of polluting, non-renewable energy sources, the use of renewable energy has gained momentum worldwide. Consequently, the increased integration of renewable energy sources into power grids has necessitated the inclusion of flexible capacities in the power systems to solve problems of intermittent and fluctuating characteristics associated with renewable generation outputs. In this work, we study the regulating cost of a power system with high renewable penetration using an improved time-series system production simulation analysis method. The operational cost of the system is considered as the objective function. Three different methods to increase regulating capacities, including using interconnection lines, building additional flexible power capacities, and retrofitting existing thermal power plants, are adopted and simulated to compare the costs of accommodating renewable energy in the system in these cases. Our results indicate that increasing the flexibility of thermal power plants and developing crossregional connection lines are cost-effective methods of increasing renewable energy consumption.

Multiple Dispatching Reactive Power and Voltage Coordinated Control Method

This paper studies the reactive power and voltage coordinated control scheme. According to the characteristics of Hunan power grid, the coordinated schemes about Hunan power grid with Central China Power Grid, as well as Changsha power grid are proposed. At the same time, this paper builds a two-way interactive and multiple dispatching reactive power and voltage coordinated control mode, and can be successfully applied in Hunan power grid. The operation results show that this control scheme fulfills the ability of large power grids in optimal allocating of resources, effectively integrates the reactive power resources of the entire grid, achieves the purpose of reducing power grid loss, improving voltage quality, reducing the operating numbers of the reactive power equipment.

Taking the Way of “Going Out”——SGCC Got the Franchise for Operating Philippine Power Grid

For Chinese power enterprises,investing overseas and actively seeking international cooperation in energy resources for mutual benefit accords with not only the desires of themselves to become bigger and stronger,but also China's energy strategy. Having won the first overseas state-level power-grid operation right,the State Grid Corporation of China (SGCC) took the lead in carrying out the strategy of "going out."

Effects of Large-Scale Wind Energy Base on Power Grid Company

The first stage project of Jiuquan wind energy base with 5.5-GW installed capacity is about to be completed. However, there exist several technical issues such as power transfer capability, electricity accommodation, frequency control and peak load regulation as well as system stability. In addition, the high capital cost and operation cost of the supporting transmission project invested and constructed by the Gansu Provincial Power Company will definitely have significant impacts on the management and economic profit of the Company. Through analysis of the construction and operation cost changes resulting from the wind power collection and delivery project, the author carried out research into the effects of developing large-scale wind power base on the management and economic benefits of power grid enterprises and proposed corresponding suggestions to make the related policies perfect.

基于柔直控制的南方电网异步联网频率同步运行控制器设计与应用

电网分区异步运行将成为未来南方电网发展趋势,针对分区异步电网间频率失去了同步性和一致性问题,开展分区异步电网频率同步运行控制策略研究,提出了分区异步电网频率同步运行控制器结构,优化确定运行关键控制参数并通过仿真验证其有效性。鲁西柔直工程作为试点实施分区异步电网频率同步运行,现场实施效果表明该控制能够有效保证分区异步运行电网间实际运行中频率的一致性和同步性,且与电网AGC策略具有良好的适配性,实施中未出现两侧电网功率振荡和频率振荡发散情况,有效改善分区电网频率稳定性和提升分区电网间功率的灵活性支援性能,同时也实现全网调频资源的实时、自动共享,推动构建全网统一的调频辅助服务市场。

面向电网调峰的盘管式冰蓄冷空调技术研究

储能是助力实现碳达峰碳中和战略目标的关键技术。当前电力供需关系的矛盾随着可再生能源高比例接入和电力需求快速增长日益尖锐,该问题在夏季用电高峰期间尤为突出。冰蓄冷空调系统在夜间利用谷电制冰储存冷量,在白天用电高峰时融冰供冷,有助于电网调峰和改善用能经济性。该文总结分析盘管式冰蓄冷空调关键技术的研究现状和发展方向。系统控制层面:对比分析冰蓄冷空调系统的各种优化控制策略;蓄冰融冰方式层面:详细阐述内融冰、外融冰和内外融冰结合3种方式特点,并对能量模型进行归纳;结构层面:分析典型强化传热方式对传热性能的影响关系。最后,归纳不同材质盘管的研究结果与应用前景。

大规模可再生能源发电友好并网与运行调控技术研究综述

“双碳”目标下大规模可再生能源系统的友好并网与稳定运行问题被广泛关注,但受精确的发电不确定性建模技术与科学的并网调控策略制约.为解决这一问题,从可再生能源发电预测与不确定性建模、可再生能源系统并网运营模式、可再生能源系统并网控制方法三个方面进行梳理和总结,讨论了不同时间尺度下发电不确定性预测技术、针对多场景运行需求的不确定性建模技术;从可再生能源-储能系统、可再生能源集群-独立储能系统、多能源互补系统三个角度分析总结了目前并网运营模式;在此基础上,分析总结了跟网型与构网型两种并网控制策略.最后展望了高比例可再生能源系统在未来电网形态演变中的发展方向,以期为新型电力系统中可再生能源与电网协同发展的研究和技术应用提供借鉴.

基于动态掺氢策略的综合能源系统低碳经济调度

针对现有综合能源系统中传统碳捕集电厂灵活性较差,电负荷系数、管道长度和管道运维成本等因素对计及气网掺氢的综合能源系统调度的影响尚未明确等问题,提出了一种基于动态掺氢策略的综合能源系统低碳经济调度模型。首先,建立综合灵活碳捕集电厂模型,对二氧化碳的吸收与再生环节进行解耦;其次,建立基于动态掺氢的管道运维成本模型,实现掺氢比的动态调整,提高系统调度的灵活性;然后,引入阶梯式碳交易机制,构建考虑气网掺氢管道运维成本的综合能源系统低碳经济调度模型,利用McCormick松弛方法将非线性问题转化为线性问题,并进行求解。最后,算例仿真结果表明:气网各节点处管道运维成本系数与气体体积、输送距离等因素相关,应综合考虑上述因素对气体定价;在综合能源系统调度中综合考虑电负荷系数、气网管道长度等因素合理选择气网掺氢比上限、制定动态掺氢策略,系统的经济效益与环境效益分别提高了44.1%、47.8%。

超级电容技术支持下电力储能功率调节系统仿真

储能过程中,相电压、相电流的频繁变化是导致电力功率无法保持稳定状态的主要原因,为解决上述问题,针对超级电容技术支持下电力储能功率调节系统进行仿真设计。在主电路传输回路中,设置有源滤波器与并网逆变器,实现对储能功率的调节,完成电力储能功率调节系统硬件单元的仿真设计。定义超级电容模型,并将其串联在电力回路中,从而在控制电力脉冲功率的同时,实施对电功率的等效调试,完成对电力系统储能功率的全面调节。

新型电力系统下分布式光伏规模化并网运行关键技术探讨

推进分布式光伏规模化并网是实现“碳达峰·碳中和”目标和构建新型电力系统的重要举措。基于此背景探讨面向新型电力系统的分布式光伏规模化并网运行关键技术。首先,归纳并阐述分布式光伏发展现状、并网方式及运行模式,分析大规模分布式光伏接入给电网调度运行带来的挑战。其次,面对上述挑战,从信息集成、监测预测、平衡调度、聚合控制等视角提出系统调度运行关键技术,助力电网调控模式转型升级。然后,考虑实际工程需求,构思满足电网安全稳定运行的分布式光伏技术标准体系,以期促使分布式光伏“可观可测、可调可控、友好互动”。最后,调研并梳理国外分布式光伏规模化并网运行先进经验,并对我国分布式光伏并网协同探索、运行服务支持及市场交易参与等课题提出建议。

太阳能光伏发电并网逆变器控制技术的应用

该文阐述光伏发电并网逆变器的控制方法,而后提出基于正弦波脉宽调制逆变技术的并网逆变器控制策略。该文旨在合理化解太阳能利用效率低下的问题,探寻出最佳的逆变器控制方法,实现零静态误差运行,并提升逆变器运行稳定性,从而将太阳能资源有效转化成为电能。

构网型和跟网型电力电子装备混联系统惯量响应的匹配问题综述

构网型和跟网型电力电子装备具有异质化调频特性,导致2类装备交直流混联系统惯量响应阶段的动态交互作用机理复杂,传统的惯量参数匹配原则难以优化系统频率响应的问题。阐述了电力电子装备系统的惯量响应匹配问题,并对现有电压源型变流器的调频控制方法进行了概述。从功频响应分析方法、调频功率分配原则和频率响应特性3个方面对电力电子装备系统惯量配置问题的研究现状展开梳理。对电力电子装备混联系统的统一建模及惯量响应匹配问题提出了研究思路,旨在通过惯量支撑功率的匹配控制提升低惯量电力系统的频率稳定性,从系统层面为高比例电力电子装备友好并网提供基础理论和关键技术支撑。

基于随机预测理论的双馈风电机组参与电网调频控制策略

随着电力系统中的风电渗透率不断提高,系统中风电功率的随机波动给电网频率稳定性带来巨大挑战。针对上述问题,该文提出基于机会约束随机模型预测控制的附加功率调频控制策略。首先,综合考虑系统中风速及负荷的实时随机波动问题,建立风电并网系统频率响应模型;其次,以系统频率变化及风电输出功率波动最小为控制目标建立期望目标函数,并将机会约束纳入随机最优化模型中;最后,根据随机扰动的分布信息或坎泰利不等式,结合状态反馈控制律求解随机最优化模型,得到当前时刻的最优控制律。利用MATLAB/Simulink搭建风电并网系统进行仿真验证,结果表明,所提策略能够有效抑制风电功率波动及系统频率变化,提高了电网的频率稳定性。

基于层次分析法的电网调度操作效率评价

基于层次分析法的电网调度操作效率评价能够从多维度评价线路操作效率、主变操作效率、母线操作效率;基于停电、复电、检修工作、许可的准时率,能够给调度操作提供辅助决策分析功能,以实现电网精益化管理。

面向燃气机组调峰的天然气管网动态安全域

燃气机组调峰的灵活性有助于提升可再生能源消纳水平,但所造成的管道压力剧烈波动却为天然气管网引入新的安全风险。该文提出一种面向燃气机组调峰的天然气管网动态安全域,以表征满足动态管流安全的燃气机组有功调整量的集合。首先,分析以时域连续的气负荷质量流率作为注入空间的天然气管网动态安全域难以实用化的原因。为此,提出将燃气机组进气口质量流率转化为有功调整量的函数,定义以初始运行点为基准、以各燃气机组有功调整量为注入空间的天然气管网动态安全域。为兼顾计算精度和效率,基于时空正交配置法对管网连续变量进行近似离散,建立安全域边界搜索优化模型。并进一步揭示天然气管网稳态安全域可通过松弛该优化模型中部分约束条件求解得到,为动态安全域的一种退化形式。算例结果表明,所提方法克服天然气管网稳态安全域对于日内安全分析过于乐观的局限性,有助于增强电力-天然气耦合系统的协同态势感知能力。