A Review of Technical Requirements for High Penetration of Wind Power Systems

Renewable portfolio targets have been established in many regions around the world. Regional targets such as 20% renewable energy by year 2020 are not uncommon. As the levels of wind power penetration increase, there are many power system impacts. This work investigated possible challenges and technical requirements for high penetration of wind power systems. The main issues to discuss covers reserve determination, wind power forecasting, unit commitment with appropriate generation portfolio, wind turbine and storage system technical development, demand response management, electricity market design, and frequency stability.

Power system planning with high renewable energy penetration considering demand response

Electric system planning with high variable renewable energy(VRE)penetration levels has attracted great attention world-wide.Electricity production of VRE highly depends on the weather conditions and thus involves large variability,uncertainty,and low-capacity credit.This gives rise to significant challenges for power system planning.Currently,many solutions are proposed to address the issue of operational flexibility inadequacy,including flexibility retrofit of thermal units,inter-regional transmission,electricity energy storage,and demand response(DR).Evidently,the performance and the cost of various solutions are different.It is relevant to explore the optimal portfolio to satisfy the flexibility requirement for a renewable dominated system and the role of each flexibility source.In this study,the value of diverse DR flexibilities was examined and a stochastic investment planning model considering DR is proposed.Two types of DRs,namely interrupted DR and transferred DR,were modeled.Chronological load and renewable generation curves with 8760 hours within a whole year were reduced to 4 weekly scenarios to accelerate the optimization.Clustered unit commitment constraints for accommodating variability of renewables were incorporated.Case studies based on IEEE RTS-96 system are reported to demonstrate the effectiveness of the proposed method and the DR potential to avoid energy storage investment.

Frequency Control of Power System with Renewable Power Sources by HVDC Interconnection Line and Battery Considering Energy Balancing

Recently, introduction of renewable energy sources like wind power generation and photovoltaic power generation has been increasing from the viewpoint of environmental problems. However, renewable energy power supplies have unstable output due to the influence of weather conditions such as wind speed variations, which may cause fluctuations of voltage and frequency in the power system. This paper proposes fuzzy PD based virtual inertia control system to decrease frequency fluctuations in power system caused by fluctuating output of renewable energy sources. The proposed new method is based on the coordinated control of HVDC interconnection line and battery, and energy balancing control is also incorporated in it. Finally, it is concluded that the proposed system is very effective for suppressing the frequency fluctuations of the power system due to the large-scale wind power generation and solar power generation and also for keeping the energy balancing in the HVDC transmission line.

Providing Frequency Support of Hydro-Pumped Storage to Taiwan Power System with Wind Power Integration

The combination of wind and pumped storage is a useful method to compensate the fluctuation of wind power generation, which would exploit the abundant wind potential and increase wind power penetration. Taiwan Power Company (TPC) develops renewable energy actively in recent years. Moreover, TPC has started planning a high penetration wind power system and building offshore wind farms around the coast of Zhangbin, Yunlin and Penghu. The target of the offshore wind power installed capacity is up to 3 GW by 2025. However, the integration of the large scale of wind power would give huge challenges to the system operator because wind is randomly characterized. In this study, after high penetration wind power is integrated, the impacts of system frequency and the dispatch of conventional units will be discussed. Additionally, the hybrid system combing wind power with pumped-storage will be planning to reduce the effect of system frequency.

Analysis and Control of Frequency Stability in Low-Inertia Power Systems:A Review

Power electronic-interfaced renewable energy sources(RES)exhibit lower inertia compared to traditional synchronous generators.The large-scale integration of RES has led to a significant reduction in system inertia,posing significant challenges for maintaining frequency stability in future power systems.This issue has garnered considerable attention in recent years.However,the existing research has not yet achieved a comprehensive understanding of system inertia and frequency stability in the context of low-inertia systems.To this end,this paper provides a comprehensive review of the definition,modeling,analysis,evaluation,and control for frequency stability.It commences with an exploration of inertia and frequency characteristics in low-inertia systems,followed by a novel definition of frequency stability.A summary of frequency stability modeling,analysis,and evaluation methods is then provided,along with their respective applicability in various scenarios.Additionally,the two critical factors of frequency control—energy sources at the system level and control strategies at the device level—are examined.Finally,an outlook on future research in low-inertia power systems is discussed.

Communication Resources Allocation for Time Delay Reduction of Frequency Regulation Service in High Renewable Penetrated Power System

The high renewable penetrated power system has severe frequency regulation problems.Distributed resources can provide frequency regulation services but are limited by com-munication time delay.This paper proposes a communication resources allocation model to reduce communication time delay in frequency regulation service.Communication device resources and wireless spectrum resources are allocated to distributed resources when they participate in frequency regulation.We reveal impact of communication resources allocation on time delay reduction and frequency regulation performance.Besides,we study communication resources allocation solution in high renewable energy penetrated power systems.We provide a case study based on the HRP-38 system.Results show communication time delay decreases distributed resources'ability to provide frequency regulation service.On the other hand,allocating more communication resources to distributed resources'communica-tion services improves their frequency regulation performance.For power systems with renewable energy penetration above 70%,required communications resources are about five times as many as 30%renewable energy penetrated power systems to keep frequency performance the same.Index Terms-Communication resources allocation,commun-ication time delay,distributed resource,frequency regulation,high renewable energy penetrated power system.

Control and Stability of Large-scale Power System with Highly Distributed Renewable Energy Generation:Viewpoints from Six Aspects

Power systems are moving toward a low-carbon or carbon-neutral future where high penetration of renewables is expected.With conventional fossil-fueled synchronous generators in the transmission network being replaced by renewable energy generation which is highly distributed across the entire grid,new challenges are emerging to the control and stability of large-scale power systems.New analysis and control methods are needed for power systems to cope with the ongoing transformation.In the CSEE JPES forum,six leading experts were invited to deliver keynote speeches,and the participating researchers and professionals had extensive exchanges and discussions on the control and stability of power systems.Specifically,potential changes and challenges of power systems with high penetration of renewable energy generation were introduced and explained,and advanced control methods were proposed and analyzed for the transient stability enhancement of power grids.

The competition and equilibrium in power markets under decar-bonization and decentralization

Equilibrium analysis has been widely studied as an effective tool to model gaming interactions and predict market results.However,as competition modes are fundamentally changed by the decarbonization and decentralization of power systems,analysis techniques must evolve.This article comprehensively reviews recent developments in modelling methods,practical settings and solution tech-niques in equilibrium analysis.Firstly,we review equilibrium in the evolving wholesale power markets which feature new entrants,novel trading products and multi-stage clearing.Secondly,the competition modes in the emerging distribution market and distributed resource aggregation are reviewed,and we compare peer-to-peer clearing,cooperative games and Stackelberg games.Further-more,we summarize the methods to treat various information acquisition degrees,risk preferences and rationalities of market par-ticipants.To deal with increasingly complex market settings,this review also covers refined analytical techniques and agent-based models used to compute the equilibrium.Finally,based on this review,this paper summarizes key issues in the gaming and equilibrium analysis in power markets under decarbonization and decentralization.

新型电力系统应对极端事件的风险防范与应急管理关键技术

保障电力安全是贯彻落实总体国家安全观的基本要求。当前,我国电力系统正向新型电力系统演进,新能源不确定性、设备低抗扰与弱支撑性等特征变化叠加日益严峻的极端事件威胁,使得提升电力系统弹性、防范电力安全风险成为一项复杂且具有挑战性的工作。该文在详细介绍新型电力系统弹性提升所面临挑战的基础上,从“风险评估—投资规划—预防准备—响应恢复”4个层面归纳新型电力系统应对极端事件的电力风险防范与应急管理技术,系统分析各层面的关键技术与研究重点。最后,对保障新型电力系统电力安全的实现路径进行展望,提出进一步深入研究的方向。

避免频率二次跌落的风储联合调频控制策略

风电高渗透电力系统中,风机释放转子动能参与频率响应改善系统频率稳定性,但存在欠响应支撑效果不足或过响应导致系统频率二次跌落现象。储能响应不受时空因素影响,通过整定储能响应参数,可提升风电频率响应的有效性。该文首先基于统一结构模型分析系统频率二次跌落与风机控制策略之间的作用机理。其次,整定充分利用风机频率响应能力及避免系统频率二次跌落的风电机组频率响应系数。然后,引入频率稳定裕度概念,并基于关系矩阵整定的储能最小出力,等效扩展系统频率稳定裕度。基于以上分析,综合考虑时空因素对系统频率响应影响,提出一种多时间尺度下避免频率二次跌落的风储联合调频控制策略。最后,基于DIgSILENT搭建风电高渗透4机4区系统进行仿真验证。结果表明,所提控制策略在不同风速下兼顾风机频率响应能力,同时避免频率二次跌落,提高全网频率安全稳定裕度。

“工业上楼”建筑电气设计要点浅析

随着经济的发展,城市产业发展往往面临产业转型升级加速和土地资源紧张的双重压力,“工业上楼”举措成为了当今城市产业发展的趋势和研究方向。“工业上楼”面向的产业类型较多,不同产业类型对电气设计的需求也不同,因此“工业上楼”建筑电气设计也相对复杂,对电气设计也带来一定挑战。本文将针对“工业上楼”建筑电气设计关键要点进行探索,以供参考。

考虑实时备用率的中长时间尺度新能源发电备用的方法

在新型电力系统中,考虑到中长期时间尺度下新能源出力具有较强规律性,提出了中长时间尺度新能源纳入备用的实时备用率的确定方法。根据实时备用率将新能源可信出力纳入备用,建立多电源电力生产模型。所建模型以生产成本最小为目标函数,考虑电源运行成本、新能源弃电成本、切负荷惩罚成本及机组出力、功率平衡、逻辑变量等约束条件。采用时间迭代将中长时间生产模拟化简为短期优化问题,利用CPLEX求解。以改进IEEE-24节点系统作为算例,优化结果表明新能源电源采用实时备用率的方法纳入备用时,电力系统生产运行总成本更低;新能源渗透率越高,纳入新能源为备用的经济效益越明显;风电和光伏独立确定备用率时,备用成本和污染排放更低。

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。

考虑灵活性供需平衡的新型电力系统长短期 储能联合规划

随着可再生能源渗透率的不断提高,以电化学储能为代表的短期储能技术将难以满足新型电力系统消纳可再生能源的需求,与此同时,灵活性也将成为系统运行特性的核心和关键。因此,提出了一种考虑灵活性供需平衡的长短期储能联合规划方法。首先,针对不同时间尺度储能技术的特点,统筹短时功率和长期能量的双重调节,考虑灵活性供需平衡并结合价格型需求响应机制,建立了以系统年化综合成本最低为优化目标的长短期储能联合规划模型。其次,为简化问题规模,利用深度卷积嵌入聚类算法在各月份提取典型场景重新刻画全年时序,并通过风光储容量规划和灵活性校验2个阶段的迭代优化求解模型。最后,以中国东部某地区为算例,验证了所提规划方法在兼顾未来可再生能源高渗透的新型电力系统规划经济性和运行灵活性方面的有效性。

面向新能源高渗透系统调峰和调频的系统级储能容量需求分析

高渗透新能源的强不确定性及火电机组占比的逐步减小使得系统灵活性资源不足,系统级储能可高效缓解系统的调峰和调频压力。为此,从系统角度提出了一种面向新能源高渗透系统调峰和调频的系统级储能需求容量确定方法。基于分位数回归分析和高斯混合模型聚类,提出了一种刻画净负荷不确定性的场景集生成方法;基于生成的场景集,建立了一种无储能容量约束的常规火电机组与储能联合优化运行模型,以获取最优运行时储能参与调峰和调频的功率;为了同时兼顾储能利用率和系统运行成本,构建了基于储能电量偏离程度、运行成本增长率指标的储能功率修正模型,并确定储能需求功率和容量,进而分析新能源渗透率、储能功率和容量与满足需求的置信度水平三者之间的关系。算例仿真结果表明,所提方法能够有效确定新能源高渗透系统调峰和调频对储能的需求容量。

基于切片采样-马尔科夫链蒙特卡洛模拟的高比例新能源电力系统等效惯量概率评估

风电、光伏新能源发电功率的不确定性给高比例新能源电力系统的等效惯量评估带来了新的挑战。基于确定性的惯量评估方法不能有效反映全分析时段高比例新能源电力系统惯量的时序变化态势。为了评估新能源波动所引起的系统惯量不确定性,该文提出了一种基于切片采样–马尔科夫链蒙特卡洛模拟(slice sample Markov chain Monte Carlo,S-MCMC)的系统等效惯量概率评估方法。首先,对高比例新能源电力系统惯量组成及特性进行了分析,并对同步旋转设备的有效机械惯量、风电光伏电源的有效虚拟惯量进行量化计算。然后,基于Copula函数建立风速和光照强度之间的相关性模型,利用S-MCMC对系统等效惯量进行概率评估,从而得到系统等效惯量时序变化区间。最后,以改进的IEEE 39节点系统进行仿真分析,验证了所提出方法及分析结果的有效性。

面向新型电力系统运行的数据-物理融合建模综述

构建新型电力系统是我国实现碳达峰、碳中和目标的关键,将给电力工业带来深刻变革与挑战。数据-物理融合建模(简称融合建模)是一类新兴的建模技术,能够同时发挥物理机理与数据的价值,有望成为新型电力系统重要的分析工具。为此,该文首先梳理融合建模的相关概念与应用场景,讨论近年来国内外的研究趋势与热点。进而从技术特征和融合模式两方面,提出针对融合模型的分析框架。同时,聚焦于新型电力系统运行领域,全方位总结整理融合建模在应对现有技术挑战方面的潜在优势及不足,并展望未来研究与工程实践的重点发展领域。

考虑长周期供需不平衡风险的新型电力系统规划方法

受高比例新能源并网带来的波动性和间歇性影响,新型电力系统的长周期供需不平衡矛盾日益突出。该文将电力系统的长周期供需不平衡风险分为两部分:连续多日无风无光的极端天气场景和月电量供需不平衡风险。首先,选取连续多日无风无光的极端天气场景,提出基于条件风险价值理论(conditional value at risk,CvaR)的月电量不平衡风险评估模型。在此基础上,提出考虑长周期供需不平衡风险的新型电力系统规划方法,通过季节性储能等灵活性资源的优化配置,可有效提升电力系统的长周期平衡能力。最后,基于IEEE RTS-79算例分析论证了所提方法的有效性,并初步讨论季节性储能在平抑长周期供需不平衡风险方面的作用。

基于多时间尺度调节的构网型储能电站定容选址优化配置

针对目前高比例新能源电力系统对电网侧储能的调节需求,提出一种基于多时间尺度调节的构网型储能电站定容选址优化配置方法。首先,为了描绘净负荷的波动性与不确定性,提出了改进迭代自组织聚类与高斯混合模型结合的多时间尺度场景集生成方法。在此基础上,建立了多场景与多时间尺度的联合优化运行模型,以处理净负荷的波动性与不确定性,并对储能容量进行优化配置。然后,分析惯性常数、储能电池循环寿命与其备用容量之间的关系,提出了一种可提升电力系统惯量与储能电池循环寿命的多目标构网型储能电站选址与容量优化方法。最后,基于中国中部某地区实际系统算例进行分析。结果表明,该方法能准确配置储能最优容量,使其满足至少90%场景下的多时间尺度调节需求。同时,利用多目标模型对储能选址与容量校正后,系统惯量分布指标与储能电池的循环寿命分别提升了28.9%和27.2%。

爱尔兰岛高比例新能源电力系统运行经验与启示

随着全球能源转型步伐的加快,世界各国电力系统均大力发展以风电和光伏发电为主的新能源。爱尔兰岛电力系统为岛屿独立同步电网,具有新能源渗透率高、与外部电网交互功率小等特点。经过长期摸索与发展,爱尔兰岛高比例新能源电力系统运行水平处于世界前列,其先进经验对我国新型电力系统建设具有重要借鉴意义。介绍了爱尔兰岛电力工业的概况,分析了爱尔兰岛电力系统的运行情况,探究了爱尔兰岛电力公司为保证高比例新能源电力系统安全高效运行采取的措施,最后总结其对我国新型电力系统建设的经验与启示。