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.

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.

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.

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.

High Proportion Renewable Energy Supply and Demand Structure Model and Grid Impaction

In considering of high proportion of renewable energy supply in 2050, the accelerating of energy consumption gross, source and environment can affect the energy system restrict affection are stronger. Add wind and solar to electricity energy with large amount of energy source exploitation. The energy source amount per person is lower. Considering the renewable energy amount and supply, primary energy storage and structure problem is standing out. Before the wide spread of renewable energy, Using the high-carbon energy in China can pollute seriously. Chinese energy supply and demand problem is research key point. This paper researches Chinese energy supply and demand pattern system and evaluation methodology, gives out the inner and outer influencing elements. And evaluate Chinese energy supply and demand pattern from energy gross, structure, distribution and transportation. Use energy supply synthesize radar comparison chart in certain time period. From energy security, economy, clean and efficiency, analyze the benefit comparisons of Chinese energy supply and demand pattern. This energy supply and demand pattern model will give one certain theoretical analysis and practice reference to the further high proportion of renewable energy.

Integrating high levels of variable renewable energy into electric power systems

As more variable renewable energy(VRE)such as wind and solar are integrated into electric power systems,technical challenges arise from the need to maintain the balance between load and generation at all timescales.This paper examines the challenges with integrating ultrahigh levels of VRE into electric power system,reviews a range of solutions to these challenges,and provides a description of several examples of ultra-high VRE systems that are in operation today.

A review of Danish integrated multi-energy system flexibility options for high wind power penetration

The current status of wind power and the energy infrastructure in Denmark is reviewed in this paper.The reasons for why Denmark is a world leader in wind power are outlined.The Danish government is aiming to achieve 100%renewable energy generation by 2050.A major challenge is balancing load and generation.In addition,the current and future solutions of enhancing wind power penetration through optimal use of cross-energy sector flexibility,so-called indirect electric energy storage options,are investigated.A conclusion is drawn with a summary of experiences and lessons learned in Denmark related to wind power development.

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。

高比例分布式可再生能源交直流混合配电网运行调控:科学问题与技术框架

随着分布式可再生能源发电与中低压直流组网技术的快速发展,未来配电网必然向复杂的交直流混合形态演进,其运行调控技术面临许多新的挑战。在高比例分布式可再生能源交直流混合配电网(HR-HDN)运行调控技术发展需求分析的基础上,提炼出HR-HDN运行调控技术的3个科学问题,并以多类型可控设备协同、源-网-荷-储高度互动化和市场化需求为研究主线,从稳定控制、故障主动防御与恢复、电力市场机制辅助调控以及“平台+数据”数字化集成调控4个方面,提出了HR-HDN的运行调控技术框架。最后,对HR-HDN运行调控关键技术的未来发展进行了展望。

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。

计及高比例新能源多种控制方式及运行约束的连续潮流

高比例新能源电网的电压稳定问题突出,连续潮流是电压稳定分析的重要工具。现有含电压源换流器(VSC)电源电网的连续潮流未充分考虑VSC的多种控制方式以及运行约束,导致电压稳定裕度计算的准确性不足。文中提出同时计及新能源并网VSC的输出电流约束和内电势约束,以及考虑构网型新能源恒电压控制、无功功率-电压下垂控制和跟网型新能源恒无功控制的连续潮流模型和计算方法,给出了由约束导致的控制方式切换逻辑和分岔点类型识别方法。通过改造的IEEE 39节点系统算例结果表明,所提模型与算法提升了传统连续潮流方法对高比例新能源电网静态电压稳定分析的适用性。

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。

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。

新能源极端出力特性及典型电力电量平衡场景研究

随着新能源发电占比的增加,电力系统的电力电量平衡呈现不确定性强、电力过剩/短缺交替出现等特征,给电力系统的供电可靠性带来了严重的影响。基于新能源出力实际运行特性和未来电源发展趋势,研究了含水电的新型电力系统的典型电源结构场景,并以此为基础,建立了电力电量平衡量化分析模型。通过算例结果量化了未来新能源发展场景下的典型电力电量平衡场景及系统灵活调节能力的需求,分析了新能源极端低/高出力对电力平衡的影响。研究可为我国新型电力系统构建提供决策参考。

计及电解铝高耗能负荷调控和火电深调的高比例风电系统分层优化策略

对于高比例风电系统,风电出力典型的随机波动性和反调峰特性极大增加了其调峰负担,火电机组深度调峰虽已常态化,但系统调峰资源仍显不足,弃风问题有待解决。提出利用电解铝高耗能负荷(electrolytic aluminum energy-intensive load,EAL)作为新的调峰资源参与电网调度。首先,根据电解铝高耗能负荷的真实生产调节特性,耦合电流、温度及产量等多种因素,建立电解铝负荷参与电网调峰的精细化调节模型;然后,结合火电机组深度调峰模型,以系统弃风量最小和运行成本最小为目标,建立电解铝负荷和火电深调联合调峰的分层优化模型;最后以某实际区域系统为例,采用商业优化软件GUROBI进行求解分析,验证了所提方案可大幅减少系统弃风量,改善系统调峰运行经济性,并优化了火电机组深度调峰结构和发电经济性。

全球高海拔地区风电利用现状综述

目前全球高海拔地区的风能资源利用率仍较低,随着陆上风电在平原等中低海拔区域的装机容量逐渐饱和,高海拔风电将是未来陆上风力发电的发展方向。为促进高海拔地区的风电发展,本文从可再生能源角度回顾了全球当前风电等清洁能源的利用概况,简述了全球能源需求及高海拔地区的能源需求,表明目前在部分高海拔国家仍存在电力不足的现象。并从全球高海拔国家的风资源潜力、装机容量等方面阐述了高海拔风电的利用现状,最后简介了我国高海拔风电的发展现状,并讨论了高海拔风电发展面临的挑战。