Assessment on Fault Diagnosis and State Evaluation of New Power Grid:AReview

1 Introduction The proposal of the concept of“New Power System”aims to illustrate the transform direction of the traditional power system,acting as the development core of the future new power grid.To achieve this,the proposed strategic targets of“carbon neutralization and carbon peaking”must be implemented and insisted[1].The core feature of the new power system is that renewable energy plays a leading role and becomes the main source of energy supply,meanwhile,the goal of green energy utilization has also been put forward on the agenda.Green energy utilization includes two aspects,one is the exploitation and promotion of various green energy technologies,and the other is the digitalization of energy management.Under this trend,stochastic and fluctuating energy sources such as wind power and photovoltaic power replace deterministic controllable power sources such as thermal power,bringing challenges to power grid regulation and dispatching,as well as flexible operation.The large-scale integration of renewable energy and increasingly high proportion of power electronic equipment tend to bring about fundamental changes in the operation characteristics,safety control,and production mode of the power system.

Steady-State Analysis of Grid-Connected New Energy Power Plants

In order to ease the fossil energy crunch,new energy sources need to be fully utilized.Clean energy sources such as wind,light,and nuclear energy are important tools to solve environmental and energy problems.However,in the process of researching new energy farms,there are some problems when they are integrated into the power system.In order to ensure the stability of new energy power plants,it is necessary to conduct an in-depth analysis of the grid connection technology of new energy farms.In the study,it is necessary to learn about the specific problems of the stability of the grid connection of new energy power plants,and to clarify the specific application of the grid connection technology of new energy power plants from the application principle and advantages of the grid connection technology of new energy power plants.Through simulation experiments,the positive effect of grid connection technology of new energy power plants in improving the stability of power systems was determined.

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.

Structured Microgrids (SμGs) and Flexible Electronic Large Power Transformers (FeLPTs)

Structured microgrids(SμGs)and Flexible electronic large power transformers(FeLPTs)are emerging as two essential technologies for renewable energy integration,flexible power transmission,and active control.SμGs provide the integration of renewable energy and storage to balance the energy demand and supply as needed for a given system design.FeLPT’s flexibility for processing,control,and re-configurability offers the capability for flexible transmission for effective flow control and enable SμGs connectivity while still keeping multiscale system level control.Early adaptors for combined heat and power have demonstrated significant economic benefits while reducing environmental foot prints.They bring tremendous benefits to utility companies also.With storage and active control capabilities,a 300-percent increase in bulk transmission and distribution lines are possible without having to increase capacity.SμGs and FeLPTs will also enable the utility industry to be better prepared for the emerging large increase in base load demand from electric transportation and data centers.This is a win-win-win situation for the consumer,the utilities(grid operators),and the environment.SμGs and FeLPTs provide value in power substation,energy surety,reliability,resiliency,and security.It is also shown that the initial cost associated with SμG and FeLPTs deployment can be easily offset with reduced operating cost,which in turn reduces the total life-cycle cost by 33%to 67%.

Key Technologies and Prospects for Electric Vehicles Within Emerging Power Systems: Insights from Five Aspects

The energy revolution requires coordination in energy consumption, supply, storage and institutional systems.Renewable energy generation technologies, along with their associated costs, are already fully equipped for large-scale promotion.However, energy storage remains a bottleneck, and solutions areneeded through the use of electric vehicles, which traditionallyplay the role of energy consumption in power systems. Toclarify the key technologies and institutions that support EVsas terminals for energy use, storage, and feedback, the CSEEJPES forum assembled renowned experts and scholars in relevantfields to deliver keynote reports and engage in discussions ontopics such as vehicle–grid integration technology, advancedsolid-state battery technology, high-performance electric motortechnology, and institutional innovation in the industry chain.These experts also provided prospects for energy storage andutilization technologies capable of decarbonizing new powersystems.

Technology and engineering application of cross area HVDC interconnection system high-precision simulation modeling based on ADPSS

In recent years, a large number of high voltage direct current(HVDC) transmission projects have been connected to AC systems. This has started to have an impact on AC/DC hybrid power grids, particularly receiving terminal power grids. An HVDC system is a large-scale power electronic integrated nonlinear system, and it includes a primary system and a control and protection system. Hence, the precision and degree of detail of HVDC systems directly affect the actual effect of simulation. In recent years, in the case of the normal operation and failure of AC power grids, the abnormal fluctuation and even locking of HVDC systems caused by the inappropriate strategies of the control and protection system component have strongly affected power grids. This has significantly affected the safety and stability of receiving power grids and normal operation. In this study, the actual engineering HVDC control logic provided by a manufacturer is analyzed and simulated based on the user defined component library of the ADPSS electromagnetic transient calculation program, and an HVDC control model based on an actual system is established. The accuracy of the DC control custom model based on ADPSS is verified through the simulation of an actual power grid.

新型电力系统中的大模型驱动技术:现状、机遇与挑战

建设新型电力系统是实现社会、经济高质量发展的重要基石,以新一代通用人工智能为主导的信息化技术与能源电力科学深度耦合,为新型电力系统的数字化转型工作提供了重要保障。为了探究电力系统在大模型时代潮流下的发展方向,该文首先系统梳理了当前电力系统的数智化发展现状以及在新的场景需求下遇到的难点问题。然后重点探讨了以多模态大模型为代表的具备深度场景解析和语言描述能力的大模型技术在电力系统中的应用前景,并分析了其在几个典型场景下的相关应用成果,证明大模型技术可行性的同时,进一步总结了大模型技术在相关电力场景所面临的机遇与挑战性问题。最后对未来大模型技术如何与电力系统实现紧密融合做了展望与建议。该研究成果有望为新型电力系统数字化转型过程中的数智化发展提供参考,助力能源电力领域提质增效。

大容量高压级联储能系统分型融合控制方法

储能的规模化应用为可再生能源高占比的新型电力系统提供重要支撑。高压级联储能系统将电池布置于级联H桥模块直流侧,是提高储能设备单机容量的有效手段。储能变流器控制方式包括跟网型控制和构网型控制两类,其中跟网型控制功率响应快速,但在弱网中易振荡失稳;构网型控制具有主动支撑能力,但存在强网适应性问题。该文提出了分型融合控制方法,实现了跟网特性与构网特性的柔性融合和灵活调节,提高了高压级联储能系统的电网强度适应性。通过仿真分析验证了所提控制方法的实用性与有效性。

构网逆变电源故障穿越控制策略及其对保护影响的研究综述

构网(grid-forming,GFM)逆变电源(inverter-based resources,IBRs)可模拟传统同步电机行为,自主提供电压以及惯量支撑,是实现高比例新能源接入电网的必然途径。继电保护是保障电力系统安全稳定运行的第一道防线,其动作性能取决于对系统故障特征的辨识能力,而构网逆变电源主导下电力系统的故障特征则与逆变电源的物理极限和控制策略高度相关。该文首先梳理了典型构网逆变电源在正常及故障穿越时的控制策略及特点;进而归纳了电源的简化等值模型及故障特性分析研究成果;最后,总结了构网型逆变电源并网系统相关的保护技术研究现状,初步评述了构网逆变电源对当前保护技术的影响以及该领域未来所面临的问题。

跟网型电化学储能虚拟惯性常数的常数化计算方法

在包含跟网型储能虚拟惯量控制的新型电力系统频率响应(SFR)建模应用中,跟网型储能的虚拟惯性常数具有时变特性,且无法聚合求解系统等效惯性常数,导致不能构建完整的SFR模型。基于此,提出了跟网型电化学储能虚拟惯性常数的常数化计算方法,通过计算具有等效惯性常数-能量支撑效果的常数化虚拟惯性常数,实现系统等效惯性常数的聚合求解。该方法根据能量变化关键节点和动态过程的约束条件,以及跟网型储能虚拟惯量响应的两阶段相异特征,建立了具有最相近能量变化的目标函数,以分段求解常数化虚拟惯性常数。最后,通过建立SFR模型,结合时域仿真法和相关评价指标验证了计算结果的精确性。

复杂大电网非预设性运行工况下的继电保护动作适应性仿真分析

非预设性运行工况下的突发事件多,导致继电保护逻辑的适应性较差,不合理区域较多,为此,进行复杂大电网非预设性运行工况下继电保护动作适应性仿真分析。分析历史常规故障,标记故障点最常发生位置,构建零序、负序方向元件模型、距离元件模型、纵联电流差动元件模型,观察复杂大电网非预设性运行工况下的电网参数变化情况,第一时间掌握电网的耦合性,不断选择电网所需的继电保护动作逻辑,确认继电保护动作适应性。仿真实验表明,将故障点设置在保护区域内和区域外,继电保护动作能够根据故障选择不同保护模型进行故障母线切除或者保护不动作,适应性好。

水电高占比下风电接入对系统稳定性影响

随着绿色清洁高效能源基地的构建,以水电为主体的水风互补成为我国西南能源开发的重要特征。为研究在典型水电系统中接入风电对系统稳定性带来的影响,首先,针对水风互补系统以转矩分析法分析了风电接入对系统频率和功角稳定性的影响,并通过算例和Prony分析验证了风速与风电渗透率对系统稳定性的影响。结果表明,风电的接入在一定程度上可以削弱传统水电系统的超低频振荡,而风电接入互联送端系统会导致区域等值惯量的下降,进而使系统区域间低频振荡风险加剧。其次,考虑风电的接入会诱发区域间低频振荡,在风电系统中引入风电的附加综合虚拟惯性与阻尼控制。算例与Prony分析验证了该控制策略能有效提高系统稳定性。最后,在区域间大规模风电接入场景下,利用改进的鲸鱼算法对风电的附加控制器参数进行了优化;结果表明,参数的整定有效提高了系统的频率以及功角稳定性。

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。

基于大语言模型的新型电力系统用户特性立体应用模式初探

随着新型负荷的广泛接入与虚拟电厂建设的不断推进,新型电力系统中多元的负荷结构与频繁的网荷交互使得用户特性应用在数据融合、特性挖掘和业务赋能面临关键挑战。因此,该文首先深入分析了用户特性的研究现状,以此为基础提出了新型电力系统用户特性立体应用模式,贯通了“多源数据-多维特性-多元模块-多样业务”的应用链路。然后,针对该模式实践中海量多源数据可用性差、特性刻画灵活性低、业务贯通复杂性高的核心技术难题,立足于近期大语言模型备受关注的显著能力与智能体应用范式,分别在自适应数据治理、对话式数据交互、自动数据分析与机器学习、多智能体应用系统架构方面提出了解决方案。进一步,更通过用电数据库交互与业扩报装接入优化的案例表明所提方案能够自动化、智能化、个性化地开展用户特性应用,有望在实际中应对用户侧业务面临的关键挑战。最后,对大语言模型赋能用户侧海量资源管控以及系统智能水平跃升进行了展望。

政策协调、不确定性与大型技术系统创新——中国核电技术赶超的案例研究

后发国家技术赶超需要实现“市场规模”和“技术自主”的双重目标,但现实中这一进程普遍面临技术依赖的“追赶者陷阱”的问题。论文采用个案内过程追踪的研究方法和“政策子系统”的分析视角,基于中国核电50年的技术赶超历程,解释了后发国家如何通过政策协调实现大型技术系统的技术赶超。研究发现,大型技术系统的创新绩效与其所在政策子系统的特性密切相关,核电政策子系统具有碎片化的结构和行为目标,需要同步进行政府部门间协调和政府对市场协调,协调机制主要包括国家意志、行政指令、共识信号和市场竞争等。政策协调通过降低大型技术系统中产业主体面临的供需不确定性,解决产业主体专用化投资不足的激励困境。跳出“追赶者陷阱”的关键在于建立国产化率目标硬约束与多种协调机制。研究进一步深化了对技术赶超中政府角色的认识,弥补了已有文献对于大型技术系统产业管理体制研究不足的理论缺口,对新型举国体制下提高系统创新能力有一定的启示。

园区受端新型电力系统电力电量再平衡方法

我国工业园区电能消耗占据了较高的比例,针对依托新型电力系统促进工业园区绿色低碳发展的需要,提出了一种面向工业园区受端新型电力系统的电力电量再平衡方法。首先,开展电力和电量需求预测并进行电力电量初平衡;然后,基于受端源网荷储协同作用并充分考虑园区节能、电能替代、各类分布式电源、储能和需求响应能力的作用进行电力电量再平衡,由此确定园区年度外调电和区内自产电的比例,进一步建立包含低碳效应和电力系统规模变化在内的量化指标评价体系,对电力电量再平衡带来的变配电容量缩减规模和降碳效用进行评价。以我国南方某工业园区新型电力系统的电力电量再平衡为例对以上方法进行了验证,结果表明:该园区2030年变配电规划容量可缩减10.1%,用电综合碳排放因子由0.60 kg/(kW·h)降至0.54 kg/(kW·h);2060年变配电规划容量可缩减9.57%,电能替代实现减碳5.85万t/a,可为受端新型电力系统的电力电量平衡提供有力的理论支撑。

基于图表映射融合技术的大电网运行业务平台化人机交互设计

为更好满足大电网运行业务中高效感知电网状态的需求,开展了软件前后端数据组织和接口设计方面的研究。在融合海量人机交互技术关键要素的基础上,提出一种大电网分析模型图模一体化与多关系表数据映射与融合的平台化技术方案,并通过2669个厂站大电网案例验证方法的有效性。结果表明,所提方法在实现诸多功能需求基础上具备较高的模型检索效率与优秀的前端渲染性能,可为大电网运行业务人机交互设计提供参考。

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。

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。