基于蒙特卡洛方法江西风电对系统的可靠性评估

风电的波动性与随机性使其在电力规划中无法与常规机组同等对待,因此,对风电的容量可信度计算显得尤为重要。而容量可信度的计算前提是风电对电力系统的可靠性评估。本文基于蒙特卡洛方法,提出了电力系统可靠性的评估研究及计算过程,并对江西省在未加入风电场与加入风电场两种情况下的系统可靠性指标进行了计算。     

大规模风电场的发电充裕度与容量可信度评估

风力发电异于常规电源的运行特性,这使得关于它的系统发电充裕度评估技术与传统方法有所不同.在通用风速模型基础之上,综合考虑风机的输出功率特性以及风向的统计分布特性,建立了风电场的发电可靠性评估模型;同时还考虑了多种尾流情况的影响,建立了尾流效应模型;并采用解析技术,在 IEEE 的可靠性测试系统中对不同实验方案下含风电场的系统总体发电充裕度和风电场的容量可信度进行评估.评估结果验证了混合考虑不同情况尾流对发电充裕度的影响程度,以及在计算时选取的风电场容量模型状态数对结果准确性的影响程度和它与系统风电穿透率水平之间的关系;还验证了风况、风场布局和风电穿透率水平等因素对等风电场的容量可信度的影响程度     

基于等可靠性准则的风电场容量可信度评估方法

风电容量可信度是衡量风力发电对电力系统可靠性贡献的重要指标。建立风速、风电机组和风电场出力模型,并考虑尾流效应,将风电场处理为等效的多状态发电机组。基于发电系统可靠性指标定义了风电场的容量可信度,采用截弦法计算得到风电场的容量可信度。以加入风电场后的IEEE RTS-96系统作为算例进行评估,通过风电渗透率、系统备用、常规机组强迫停运率等因素对风电场容量可信度的影响分析,验证了该方法的正确性和有效性。     

基于相关机会规划的风电并网容量优化分析

风能的随机性和间歇性强,所以与传统发电形式相比,风电场容量可信度低,如何计算系统中的最大风电并网容量是风电规划所面临的重要问题。基于相关机会规划理论,在保证系统安全运行的前提下建立了计算风电并网容量的优化分析模型,模型中引入了风电的发电能力约束,并考虑了风电场减出力控制措施的影响。该模型适用于不确定环境下的随机事件评估,基于IEEE39节点系统的风电并网容量优化结果验证了模型的可行性。     

考虑多风电场出力相关性的风电容量可信度评估方法

风电容量可信度是衡量风力发电对电力系统可靠性贡献的重要指标,准确快速地计算风电场可信容量是含风电系统规划的基础。处于同一风区空间位置临近风电场出力具有相关性,采用Copula函数描述空间相邻风电场之间的出力相关关系,构建多风电场出力的联合概率分布模型。在此基础上提出出力相关的多风电场容量可信度评估方法,并采用截弦法计算得到风电场的容量可信度。以加入风电的IEEE RTS-96系统为例,仿真结果验证了所提方法的正确性和有效性。     

基于运行可靠性的风电容量可信度研究

现有风电容量可信度的研究通常属于系统规划层面,难以直接指导实际生产运行。从运行层面出发,研究风电运行容量可信度及其影响因素,分析了其对调度计划的指导作用。首先针对风电预测误差与预测出力之间的相关关系,建立多风电场预测误差的条件概率分布模型;其次建立风电和常规机组的等效容量分布模型并进行运行可靠性评估;继而提出运行层面风电容量可信度的定义及评估方法;最后结合实际风电数据和测试算例,对不同时间尺度运行容量可信度进行计算,得出风电运行容量可信度的相关结论,为大规模风电接入后的调度运行提供决策支持。     

含风/光发电系统的复合电力系统可靠性评估

为了保证电力系统安全稳定的运行,需对电力系统进行可靠性评估。针对风电场和光伏电场接入电力系统后对电力系统可靠性的影响,提出了风电场及光伏电场的多态分析模型。建立了可再生能源发电系统的可靠性模型,并将元件故障率及可再生能源的不确定性都考虑在内。采用状态枚举法和条件概率建立了电力系统的概率模型。利用模糊C-均值聚类算法对状态模型进行分析。对加入风电与光伏发电的RBTS和IEEERTS测试系统进行可靠性评估,计算得到不同的可靠性指标。实验结果充分证实了所提出方法的简单性与准确性。     

风电场容量可信度及其若干影响因素分析

风电场的容量可信度是衡量其发电容量价值的基本指标,也是风电场规划选址的一个重要参考依据,为此．首先采用时间序列分析法模拟每小时的风速值．并结合风电机组的强迫停运率等数据,建立风电场的可靠性模型：其次．采用抛物线法计算风电场的有效载荷容量：最后利用序贯蒙特卡罗模拟法,研究胍电场的容量可信度。该方法不仅可计及风速的时序性．还能准确评估系统的频率指标。在此基础上,通过IEEE—RTS79标准算例仿真计算．对比分析采用不同指标衡量系统可靠性时．容量可信度计算结果的差异．并研究影响容量可信度大小的主要因素。     

风电并网后电力系统可靠性评估和备用优化研究

为了定量研究风电并网对电力系统的可靠性和备用配置影响,基于蒙特卡罗方法和粒子群优化算法给出了一种风电并网后的电力系统可靠性评估和备用优化模型。利用历史风速数据统计得到风机的出力概率分布图,并利用蒙特卡罗算法,对各种条件下风电并网后的电力系统进行了可靠性评估。设计了一种基于可靠性指标的备用优化模型,利用粒子群算法对比优化前后所需备用容量的大小。测试算例评估结果表明,不同接入容量、接入点和接入方式对最后的电力系统可靠性影响不同,并得到了不同容量下的风电场容量可信度,为含不同风电入网容量下的电力系统调度提供了备用量化指标。加入实际系统后的进一步研究表明了风电并网后备用优化的有效性和必要性。     

风电场可靠性建模

考虑风速和风向的随机变化、风电机组的功率特性、不同风电场之间风速的相关性以及风电机组停运模型、风电场尾流效应和气温的影响,建立了风电场可靠性模型及尾流效应模型。仿真结果验证了所提模型的有效性。该模型为进一步研究含风电场的电力系统可靠性评估、风电场容量可信度以及其他风电场并网问题打下了基础。     

风电容量充裕性成本分析模型和方法研究

风电容量可信度低,大规模风电并网将大幅增加电力系统的容量充裕性成本是电力规划和运行中需要重点考虑的一个问题。对风电并网对系统容量充裕性影响机理进行深入分析,提出了风电容量充裕性成本的分析模型和方法,建立了基于有效负荷承载能力算法（ELCC）的风电容量可信度计算模型和基于容量可信度的充裕性成本计算模型。案例研究表明,随着接入风电规模的增加,该省级电网的风电容量可信度随之下降,而风电引起的容量充裕性成本逐步上升。当风电发电量占用电量比量达到10%时,对应的容量充裕性成本已高达0.06元/（kW·h）。     

基于互转换Ornstein-Uhlenbeck过程的风速仿真模型及应用

准确的风速仿真是研究含风能发电系统的重要且基础步骤。为此,提出基于互转换Ornstein-Uhlenbeck过程的风速仿真模型,该模型可产生任意时间步长的仿真风速样本,将其与时序Monte Carlo模拟法结合,提出仿真时间步长可变的含风能发电系统充裕度评估方法。然后,采用某观测站的实测风速样本验证所提模型,结果表明,模型产生的不同时间步长仿真风速样本具有与实测风速样本类似的概率分布特征和自相关特征。应用充裕度评估方法评估含风能IEEE-RTS发电系统充裕度,结果表明,期望失电频率对仿真时间步长的敏感度高于期望失电持续时间和期望失电量对仿真时间步长的敏感度,较大的仿真时间步长将导致对期望失电频率的过低估计,充沛的风能资源可增大风电场并网的充裕度效益。     

Comprehensive evaluation model of windpower accommodation ability based onmacroscopic and microscopic indicators

This article explores and establishes comprehensive evaluation index system of wind power accommodation ability considering microscopic index and macroscopic index, and the index system includes conventional evaluation indexes such as forecast deviation, simultaneity factor and anti-peak rate, also newly introduced evaluation indexes such as installed capacity, power adequacy and accommodation space. Bayesian weight modified method is used for solving index weights of 8 wind power accommodation indexes. The paper puts forward a comprehensive evaluation model of wind power accommodation ability based on improved radar chart method, and this model changes traditional radar chart fan-shaped sector to quadrilateral evaluation region, and increasing angle bisector can solve the problem that evaluation results are not unique. It constructs new area and perimeter vectors of radar chart, which make the evaluation results give consideration to level of aggregation and balance degree of evaluation objectives, and case study results show that this model has a certain practical value.     

风/柴/储能系统发电容量充裕度评估

提出一种用于含风能和能量储存设备的小型孤立电力系统(SIPS)发电容量充裕度评估仿真方法。该仿真方法根据每小时计算的随机事件模拟发电系统的运行历史记录,考虑现场风资源的时序性、系统中发电机组的故障和修复特性。使用几个样例系统说明了该方法的应用,该系统的充裕度取决于许多因素,它们是能量储存容量、系统负荷需求、风能注入水平、发电机组强迫停运率(FOR)和其地理位置。能量储存设备对该系统可靠性能有积极的影响;SIPS随着系统负荷的增加,充裕度减少;风力发电机组FOR的变化对系统充裕度的影响不大;增加风能注入水平可以改善可靠性;位于高平均风速处的系统明显比低平均风速处的系统可靠性高。     

Renewable energy credit driven wind power growth for system reliability

Environmental concerns over electric power generation from conventional sources has led to widespread public support for renewable energy sources. Governments throughout the world have responded by providing various forms of financial incentives to promote power generation from renewable energy sources. The rapid growth of wind power since the last decade has primarily been driven by governmental subsidies. Long-term growth of wind power should, however, be driven by sustainable market mechanisms. A potential solution is to recognize monetary values to the environmental benefits from renewable energy sources, and to specify targets for their growth. The environmental benefits from wind sources can be leveraged to allow market competition of these sources with the less costly conventional generating sources. A probabilistic method to evaluate the impact of renewable energy credit and wind penetration level on the cost and adequacy of power generating systems is presented in this paper. The technique incorporates reliability and economic analyses and is applied to a published test system to illustrate the results and their influence on key system variables. The paper provides useful information to system planners and policy makers on wind energy application in electric power systems.     

A meteorological information mining-based wind speed model for adequacy assessment of power systems with wind power

Accurate wind speed simulation is an essential prerequisite to analyze the power systems with wind power. A wind speed model considering meteorological conditions and seasonal variations is proposed in this paper. Firstly, using the path analysis method, the influence weights of meteorological factors are calculated. Secondly, the meteorological data are classified into several states using an improved Fuzzy C-means (FCM) algorithm. Then the Markov chain is used to model the chronological characteristics of meteorological states and wind speed. The proposed model was proved to be more accurate in capturing the characteristics of probability distribution, auto-correlation and seasonal variations of wind speed compared with the traditional Markov chain Monte Carlo (MCMC) and autoregressive moving average (ARMA) model. Furthermore, the proposed model was applied to adequacy assessment of generation systems with wind power. The assessment results of the modified IEEE-RTS79 and IEEE-RTS96 demonstrated the effectiveness and accuracy of the proposed model.     

风电与常规电源联合外送的受端可信容量研究

可信容量作为衡量电源对电力系统贡献程度的重要标志在电力系统规划中受到广泛关注,目前研究中往往仅考虑发电机组可靠性而忽略输电线路可靠性。针对中国风电与常规能源联合外送的实际情况,在可信容量的基础上提出能源基地受端可信容量的概念及其计算方法。对输电线路进行序列化建模,并利用基本序列运算实现了考虑输电线路可靠性的2节点电力系统生产模拟过程,进而评估能源基地各类电源对于受端电网的可信容量。采用加入风电后的IEEERTS-79算例测试了算法的有效性,同时研究了风电与常规能源联合外送情况下受端可信容量的影响因素。     

Multi-objective transmission expansion planning considering minimization of curtailed wind energy

This paper proposes a new multi-objective transmission expansion planning (TEP) in order to find optimum location of lines/transformers by considering intermittent nature of wind power and variable load structure. To reveal the benefit of wind power in the context of TEP, curtailed wind energy is considered as one of the objective functions besides the sum of the investment costs and penalty for energy not supplied (ENS). By this way, a trade-off between investment cost and curtailed wind energy is established using fuzzy satisfying approach while maintaining the adequacy of power system. The multi-objective nature of the proposed method is handled by using the Non-dominated Sorting Genetic Algorithm-II combined with the DC-optimal power flow which is performed several times to obtain curtailed wind energy and ENS. The nature of load and wind power is incorporated into the methodology by using agglomerative hierarchical clustering to reduce computational effort. The proposed methodology is illustrated on the different configurations of modified IEEE-RTS 24 bus test system. Numerical case studies indicate the effectiveness of the proposed method for reduction of total investment cost in TEP of power systems with wind power integration.     

Reliability assessment of bulk electric systems containing large wind farms

Wind power is an intermittent energy source that behaves quite differently than conventional energy sources. Bulk electric system reliability analysis associated with wind energy conversion systems (WECS) provides an opportunity to investigate the reliability benefits when large-scale wind power is injected at specified locations in a bulk electric system. Connecting the WECS to different locations in a bulk system can have different impacts on the overall system reliability depending on the system topology and conditions. Connecting a large-scale WECS to an area which has weak transmission could create system operating constraints and provide less system benefit than connecting it to an area with stronger transmission. This paper investigates bulk electric system transmission constraints associated with large-scale wind farms. The analyses presented in this paper can be used to determine the maximum WECS installed capacity that can be injected at specified locations in a bulk electric system, and assist system planners to create potential transmission reinforcement schemes to facilitate large-scale WECS additions to the bulk system. A sequential Monte Carlo simulation approach is used as this methodology can facilitate a time series modeling of wind speeds, and also provides accurate frequency and duration assessments. An auto-regressive moving average (ARMA) time series model is used to simulate hourly wind speeds.     

风能大规模利用对电力系统可靠性的影响

风是一种非常易变的能源，其表现与其它形式的能源有很大不同。该文使用时序蒙特卡洛模拟法，提出一种含风能电力系统发电容量充裕度评估的方法，使用一个有代表性的可靠性测试系统(reliability test system，RBTS)阐述了该方法，此系统既含有常规发电机组也含有风能转换系统(wind energy conversion system，WECS)。对含有一个风场和多个风场混合系统的可靠性进行分析计算，结果表明，风能利用具有很大的可靠性效益，使用所提方法，可以量化这些效益。