UPFC对电网可靠性的灵敏度分析及优化配置

从改善发输电系统可靠性的角度出发,采用统一潮流控制器(UPFC)的功率注入模型,将UPFC纳入传统最优负荷削减模型中。利用该模型中UPFC不等式约束中控制参数的拉格朗日乘子的物理意义,推导了系统电量不足期望对UPFC容量的灵敏度表达式,提出了根据该灵敏度排序结果确定UPFC最优安装位置的方法;然后以UPFC投资费用与用户停电损失之和最小为目标,确定UPFC最优安装容量。对RBTS和IEEE-RTS79可靠性测试系统的仿真研究验证了所提出的UPFC优化配置方法的有效性。     

基于节能发电调度的减少电网水电旋转备用的研究

从某省级电网水电资源丰富、水电装机比重较大的实际情况出发,依据节能发电调度原则,开展了基于节能发电调度的减少电网水电旋转备用的研究,对该省电网实现节能发电调度中的水电旋转备用问题进行了研究.开发相关辅助决策软件,通过优化系统快速旋转备用容量,实现了节能、环保的目的.     

考虑风电备用可靠性的电力系统备用优化

风电能够以降载运行的方式提供备用。由于风电实际出力的不确定性,风电提供的备用也可能偏离预定值,风电备用并不完全可靠。为此提出一种考虑风电备用可靠性的电力系统备用优化模型。首先,基于风电出力的概率分布信息,分析风电提供备用的变化;然后,将风电备用纳入弃风、失负荷成本的计算中,并通过进一步的消除积分符号以及线性化处理,将模型转化为混合整数线性规划问题求解;最后,基于IEEE-RTS 24节点算例验证了所提模型的有效性。算例结果表明,考虑风电备用的可靠性可以对系统中的弃风、失负荷成本进行更精细的评估,从而对系统中的备用进行更精细的配置,避免过于保守或激进的结果。     

基于条件成本收益分析的旋转备用优化配置

电力系统需要权衡可靠性和经济性以实现旋转备用的优化。基于整体均值的传统可靠性评估方法和指标,将高损失—低概率事件与低损失—高概率事件同质化,无法反映决策者的风险偏好和关注的损失范围,也无法体现旋转备用配置对极端损失情形的敏感性。文中引入条件可靠性评估的方法和指标,建立条件成本收益分析模型,在决策者关注的风险范围内优化旋转备用。通过逐时段地进行时序解耦的机组组合,确定运行成本和开机方式;再对在线机组进行状态抽样,计算条件可靠性成本,确定使该时段条件总成本最小的条件最优旋转备用容量。最后,进行一次完整约束的机组组合,将备用要求分配至机组。算例表明,决策者的主观风险偏好对最优旋转备用方案有显著影响,随着关注的损失范围由整体平均转向极端不利,系统对旋转备用的需求持续提升,甚至超出现有装机容量的提供能力。     

基于系统频率响应特征的电网广义旋转备用优化配置

现有的旋转备用配置方法多将旋转备用的来源限定于常规发电机组,较少虑及储能装置与柔性负荷等新兴电力设施对旋转备用优化配置的积极影响。为此,文中提出了电网广义旋转备用的概念;借助序列化建模思路与可描述随机变量取值相依结构的Copula函数,建立电网等效负荷(电网原始负荷与对应时刻点新能源发电出力的差值)波动量与预测偏差模型;综合考虑系统频率响应特征,以电网广义旋转备用购置成本、停电损失成本与弃新能源发电成本最低为目标,提出一种基于系统频率响应的新能源高渗透电网广义旋转备用优化配置方法。以新疆某新能源高渗透区域电网实际运行数据为依据,仿真验证了所提方法的可行性。     

电网备用容量可靠性研究

综述了国内外大型电网在确定运行备用容量时所采用的方法及其特点。指出合理的配置电网备用容量,是电网安全、优质运行的根本保证。从通行的评估电网可靠性方法出发,详细分析了各种评估方法的优缺点,提出采用概率分析法,来评估电网预留备用容量。而通过概率方法得出的一系列可靠性指标,可以指导电网运行者合理的预留和分配电网备用容量。最后,指出了电网备用容量可靠性研究的具体实施方法、步骤,以及今后的发展方向。     

水电站提高可靠性效益和旋转备用效益计算

水电站具有事故率低、运行灵活、增荷速度快等特点。用水电站承担负荷和旋转备用，可减少电力系统电力电量损失，提高供电质量，产生经济效益。本文采用替代法，分别以系统年期望强迫停运电能和电量不足期望值作为计算指标，研究了水电站提高供电可靠性效益和旋转备用效益的计算方法，分析了系统旋转备用设置和负荷预测偏差对水电站旋转备用效益的影响。     

适应大规模新能源并网的电力系统备用配置及优化综述

大规模新能源并网后,传统的备用体系在应对电力系统电源侧及负荷侧存在的双侧随机性时,存在经济性及可靠性欠优的问题,为保证系统安全稳定运行,需要对系统备用的配置及优化方法进行研究。文中阐述了大规模新能源并网对电力系统备用的影响,充分挖掘系统多类备用资源;并阐述了电力系统源、荷、储3类备用资源及其作为互联电网跨区备用的研究现状,用以应对大规模新能源并网环境下系统面临的各类长时间、大扰动、大容量功率缺额风险事件;详细分析了电力系统备用现有的各类容量配置方法及调度优化方法,并指出下一阶段的研究方向,为后续大规模新能源并网下电力系统的备用配置及优化方法研究提供参考。     

旋转备用市场中考虑可靠性的多目标分层决策

电力市场环境下旋转备用的出清结果对发电系统可靠性有着重要影响.提出了对运行阶段发电系统可靠性进行评估的新指标--考虑旋转备用的电力不足期望值,它综合了机组可靠性参数、爬坡率、投运时间以及电能和旋转备用市场出清结果对系统可靠性的影响.指出用排队法进行旋转备用出清的结果只是满足购买费用最小的一个非劣解,进而提出考虑可靠性的多目标分层决策模型,并用遗传算法和非线性优化算法求解.仿真结果表明了该方法的有效性.     

A tradeoff between unit capacity and average production cost in spinning reserve optimization

In power systems the spinning reserve (SR) amount can be determined by deterministic or probabilistic techniques. Probabilistic techniques draw more attention since they can consider the economics and the stochastic nature of system behavior and component failures. In probabilistic techniques, the tradeoff between cost and reliability directly affects the SR deployment and it has been extensively analyzed. However, there is another tradeoff which reflects the compromise between the unit capacity and average production cost in the SR optimization problem. This tradeoff impacts the solution accuracy to a certain extent and influences the complexity of the model, and it has not been explicitly analyzed before. In this paper, a new SR optimization method is proposed in which the tradeoff between unit capacity and average production cost is well respected. The proposed method strikes a good balance between solution accuracy and computation efficiency and can obtain better results within a desirable run time compared with those of the previous methods. Besides, the proposed method can also be used to improve the solution of the reserve constrained unit commitment problem. It can lower the total cost by just redistributing the MW dispatch even when the SSR is fixed. The efficiency and validity of the proposed method are verified using the IEEE reliability test system.     

发电厂热备用容量的优化分配和成本分析

在竞争的发电市场环境下，备用作为一种重要的辅助服务，其成本分析是一个急待解决的问题，对发电厂热备用容量进行优化分配和成本分析，采用电能收益和备用容量收益总和最大化的目标函数。解算方法首先是根据发电厂总的发电负荷约束获得机组的经济组合，其次是将负荷在各机组间进行经济分配实现热备用容量的优化分配，热备用容量的成本采用其机会成本等值，方法简单，计算结果符合工程实际，研究结果表明，发电厂在计及备用收益和满足发电机组最低出力约束的条件下开机台数越多总收益也越大；在给定的时段和相应的电能电价下，备用容量成本随发电厂出力的增加而增加，在给定的时段和相应的发电出力下，备用容量成本随电价的增加而有较大的增加。     

Cost allocation of spinning reserve based on risk contribution

Current cost allocation methods require generating companies (GENCOs) to afford spinning reserve (SR) costs according to their energy production rather than the impact on grid stabilization. The differences in generator reliability and forecast accuracy of renewables cause difficulty in quantifying the contribution of individual factors on the SR requirements (SRRs). First, this paper employs a reliability‐constrained unit commitment (RCUC) model to determine the SRR and SR costs according to the grid reliability. Then, a cost allocation method is proposed to allocate these SR costs based on risk contribution theories. The risk contribution theories, marginal contribution, and stand‐alone contribution are employed to measure the effect of individual risk factors on grid safety. The cost allocation method is demonstrated and discussed in the IEEE‐RTS. The proposed risk contribution method can quantify the impacts of risk factors on grid safety and allocate SR costs into them according to their contributions. Additionally, this risk‐based cost allocation method can encourage GENCOs to enhance the reliability level of generators and continuously improve the forecast accuracy of renewables to lower SR costs. © 2015 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Composite power systems reliability evaluation based on demand-side reserve

This paper proposes new demand-side reliability indices and useful computational methods for reliability evaluation of composite power systems. These new indices are based on the active power which can reach each demand spot under generating and transmission network constraints. This conception is defined as “reachable power,” and it leads the reserve margin on each demand spot, which is called as “demand-side reserve.” If the reachable power is insufficient to satisfy the demand, load curtailment is required. In the proposed approach, the conception of the load curtailment area is defined, and the estimate method of load curtailment area is indicated. In case the reachable power exceeds the demand, system reliability is evaluated by the demand-side reserve, and the power system is divided into several reliability zones according to the demand-side reserve levels. Small system examples are used to illustrate principles of the proposed approach, and middle system examples show the effectiveness and practicality.     

Customer choice of reliability in spinning reserve procurement and cost allocation using well-being analysis

A novel pool-based market-clearing algorithm for spinning reserve (SR) procurement and the cost allocation associated with provision of spinning reserve among customers (DisCos) is developed in this paper. Rational buyer market model is used to clear energy and spinning reserve markets in the proposed algorithm. This market model gives DisCos the opportunity to declare their own energy requirement together with their desired reliability levels to the ISO and also they can participate in the SR market as a interruptible load. The DisCos’ desired reliability levels are selected from a hybrid deterministic/probabilistic framework designated as the system well-being model. Using the demand of each DisCo and its associated desired reliability level, the overall desired system reliability level is determined. The market operator then purchases spinning reserve commodity from the associated market such that the overall desired system reliability level is satisfied. A methodology is developed in this paper to fairly allocate the cost associated with providing spinning reserve among DisCos based on their demands and desired reliability levels. An algorithm is also presented in this paper for implementing the proposed approach. The effectiveness of the proposed technique is examined using the IEEE-RTS.     

旋转备用辅助服务的需求与调度

备用辅助服务关系到电力系统的安全运行和可靠性。旋转备用与能量市场有很强的耦合关系,其容量需求和调度分配受到了人们的广泛关注。该文采用和能量市场解耦的旋转备用辅助服务模式,提出了以系统旋转备用社会效益最大的最优备用容量确定原则和基于竞争的备用分配调度模型。文中采用启发式算法求解,算例的仿真结果说明了该方法的有效性。     

基于多时间尺度协调机组组合的含风电系统 旋转备用优化研究

考虑风电出力的预测误差和负荷功率的预测误差具有随预测时间尺度的缩短而减小的特点,以及电力系统旋转备用容量的配置离不开机组组合,建立了多时间尺度下协调机组组合的含并网风电电力系统旋转备用预留容量的优化模型。对该模型的求解,先采用优先顺序法求取各机组的启停机顺序,再通过粒子群算法滚动计算求解得出不同等效旋转备用容量水平下所对应的系统最经济调度计划。通过利用不断更新的风电出力预测和负荷预测结果信息来调整调度计划,在保障系统可靠性达到要求的前提下,减少含风电电力系统旋转备用容量的配置,从而提高风电并网后电力系统运     

基于多时间尺度协调机组组合的含风电系统旋转备用优化研究

考虑风电出力的预测误差和负荷功率的预测误差具有随预测时间尺度的缩短而减小的特点,以及电力系统旋转备用容量的配置离不开机组组合,建立了多时间尺度下协调机组组合的含并网风电电力系统旋转备用预留容量的优化模型。对该模型的求解,先采用优先顺序法求取各机组的启停机顺序,再通过粒子群算法滚动计算求解得出不同等效旋转备用容量水平下所对应的系统最经济调度计划。通过利用不断更新的风电出力预测和负荷预测结果信息来调整调度计划,在保障系统可靠性达到要求的前提下,减少含风电电力系统旋转备用容量的配置,从而提高风电并网后电力系统运行的经济性和系统吸纳并网风电的能力。     

微网功率不确定性模型及其在旋转备用优化中的应用

微网运行中存在发电单元故障停运以及可再生能源发电单元出力和负荷的波动性,从而合理安排旋转备用容量是维持微网安全、经济运行的重要环节。基于风电出力、光伏出力和负荷日前预测误差模型,利用全概率公式分别构建了综合预测误差及故障停运的风电和光伏出力不确定性分布模型,通过离散化风光出力和负荷不确定性分布与可调度机组停运概率分布联合生成微网功率不确定性离散分布模型,进而提出了计及微网功率不确定性以微网运行成本最小化为目标函数的微网最优旋转备用计算模型并考虑了微网向主网提供旋转备用。最后通过一个微网系统算例,采用混合整数遗传算法优化求解微网最优旋转备用值,验证了所建模型的合理性。     

基于加权半方差的含风电电力系统旋转备用效益研究

在考虑系统旋转备用的容量成本和能量成本、因购买旋转备用而减少的停电损失,以及旋转备用效益的离散程度的基础上,引入风险偏好系数,并采用证券投资组合中的加权半方差度量风险。以期望旋转备用效益最大和风险最小为优化目标,建立基于加权半方差的含风电电力系统旋转备用效益-风险模型。采用蒙特卡洛模拟法模拟实际负荷功率偏差和风电出力预测偏差,并通过多目标纵横交叉算法求得期望旋转备用效益-风险有效前沿和日前旋转备用计划,以及风险偏好系数、可靠性水平、预测偏差、失负荷损失价格、旋转备用价格对期望旋转备用效益和风险的影响。算例验证了所提模型的合理性。