Evaluation of the marginal outage costs of generating systems forthe purposes of spot pricing

This paper describes a methodology based on quantitative power system reliability evaluation for calculating the marginal outage costs of generating systems. The proposed method involves the calculation of the incremental expected unserved energy at a given operating reserve level and lead time and the multiplication of this value by the interrupted energy assessment rate of the system. The method is illustrated in this paper by calculating the marginal outage cost profile of the IEEE-Reliability Test System and by examining the effect of various modelling assumptions on that profile     

基于概率潮流的风电分布式电源优化配置

由于风电机组输出功率的随机波动性,使得基于风电机组的分布式电源并网后,给配电系统的结构和运行带来巨大变化,影响系统的安全性和可靠性。在含分布式电源的配电网系统规划中,对分布式电源进行合理选择和配置是发挥最大效益的关键。采用Weibull分布来描述风速的随机变化,并计及风电机组强迫停机率的影响,结合功率曲线,建立风力发电的概率分析模型。通过Cornish-Fisher级数交流概率潮流计算方法,分析风电和负荷的随机波动对含分布式电源配电系统的影响,利用混合整数非线性规划方法,确定风电系统的最佳接入点和注入容量使得系统有功网损最小。     

PEA Guidelines for Impact Study and Operation of DG for Islanding Operation

Intentional islanding operation of distributed generation (DG) can increase system reliability and reduce customer outage costs. Guidelines for the impact study and operation of DG for islanding operation should be implemented. The Provincial Electricity Authority (PEA) plays more attention to intentional islanding operation. To perform islanding operation, PEA has established islanding operation and impact study guidelines for DG. This paper presents the development of these guidelines. A case study was conducted to demonstrate the results of both steady-state and dynamic analyses. Operational issues are also taken into account in this paper.      

Value-based distribution system reliability planning

Society is becoming increasingly dependent on a cost-effective reliable electric power supply. Unreliable electric power supplies can be extremely costly to electric utilities and their customers. Predictive reliability assessment combines historical outage data and mathematical models to estimate the performance of specific network and system configurations [e.g., IEEE Std. 493-1990]. This paper is concerned with the value-based assessment of proposed modifications to an existing industrial distribution system configuration to minimize the costs of interruptions to both the utility and its industrial customers. This paper presents a series of case studies of an actual industrial load area supplied by two feeder circuits originating from two alternate substations. Each case study reveals the impact on the cost of industrial load point interruptions and the frequency and duration of industrial load point interruptions when various system constraints (e.g., ideal and nonideal protection coordination schemes, substation capacity restrictions, etc.) are imposed on the distribution system. The paper discusses in some detail the variance in reliability performance indexes and their impact on the cost of load point interruptions. A basic conclusion of this paper is that expansion plans of an industrial distribution system can be optimized in terms of reliability by using an economic criterion in which the sum of both the industrial facility interruptions and the utility system costs are minimized     

联网分布式发电系统规划运行研究

分布式发电（DG）与输电网联合供电成为电力系统发展趋势。输电系统与DG联合供电的规划、运行分析对满足可靠性条件下的经济供电尤为重要。文中针对远离发电中心、与输电系统弱连接的配电系统,为了满足负荷增长要求,以DG投资费用和向输电网购电费用最小为优化目标,分别对输电网正常运行且价格固定、考虑停运状态和实时电价3种典型输电网情况下联网DG系统进行规划。通过应用启发式算法,得到了各种情况下系统最优供电方案。根据不同情况下系统运行性能分析,定量讨论了输电网停运、实时电价以及可再生能源随机发电对分布式电源类型、容量等规划运行结果的影响,优化结果体现了联网DG系统联合供电优势。     

计及配网停电损失的DG双层规划方法

分布式电源发电商与配电网公司利益共赢是促进能源战略落地的重要保障.文中提出了一种计及配电网停电损失的分布式电源双层规划方法.上层模型以DG发电商收益最大化为目标,基于网损灵敏度方法确定DG候选安装位置,对DG的选址和定容进行优化;下层模型以配电网公司净收益最大化为目标,通过孤岛划分方法动态优化分段开关安装位置,减少配电...     

Impact Study on Intentional Islanding of Distributed Generation Connected to a Radial Subtransmission System in Thailand's Electric Power System

Traditional interconnection standards avoid the islanding operation of distributed generators (DGs) because of concerns of equipment failure and safety. However, in some cases, allowing the islanding operation of DGs in a radial subtransmission system could improve system reliability and decrease outage cost during power outages or a scheduled maintenance. This paper presents an impact study on a DG connected to a radial subtransmission system. The dynamic study is conducted to show how to manage DGs and electric power systems for the proper intentional islanding in specific cases.     

面向用户需求的DG与配网网架多目标联合规划

考虑电力用户的多样化供电需求和可再生能源DG出力随机性,提出了面向用户需求的DG与配网网架多目标联合规划方法。根据用户对供电电压质量和可靠性等多样化的需求,对负荷需求整理分类;根据可再生能源DG出力的概率模型和机会约束规划方法,处理不确定性问题;以年社会成本、电压偏移率和用户停电缺失量综合最优为目标函数,建立了DG与配网网架多目标联合规划模型。基于pareto优化理论,采用多目标混合粒子群算法和熵权修正的AHP-TOPSIS多属性决策策略相结合的方法,求解模型。最后,利用算例验证所建模型的合理性和有效性。     

基于EPSILON约束法的配电自动化设备多目标优化布点模型

通过在配电网中配置自动化设备可以有效限制故障带来的负面影响,从而提高供电可靠性,减少停电损失,但采用全覆盖式的布点方案会极大程度地加剧电力公司的资金压力。为了合理地配置各类自动化设备,最大程度地发挥资金效能,提出了配电自动化设备的多目标优化布点模型。首先,分析了各类设备布点情况与负荷停电时间之间的关系,进而获得了供电可靠性与停电损失关于设备布点情况的表达式。然后,以各类设备的全生命周期费用作为约束,搭建了基于混合整数线性规划的配电自动化设备多目标优化布点模型,并通过数学求解器配合EPSILON约束法对其进行求解,以有限的资金获得最大的供电可靠性以及最小的停电损失。最后,基于IEEE RBTS-BUS4的算例结果表明,所提出的模型可以精确有效地对配电自动化设备进行优化布点,并直观地反映供电可靠性与停电损失之间的关系,为电网规划人员提供了辅助材料。     

Reliability Evaluation for Distribution System With Renewable Distributed Generation During Islanded Mode of Operation

Keen interest in the development and utilization of wind-based distributed generations (DGs) has been currently observed worldwide for several reasons. Among those is controlling the emission of environmentally harmful substances, limiting the growth in energy costs associated with the use of conventional energy sources and encouraging the independent power producers for participation in the electricity market system. One of the most important issues is to quantitatively assess the impact of such type of DGs on the distribution system reliability. This paper presents a probabilistic technique to evaluate the distribution system reliability utilizing segmentation concept and a novel constrained Grey predictor technique for wind speed profile estimation.     

Comparison of alternative techniques for evaluating the marginaloutage costs of generating systems

Quantitative evaluation of the marginal outage costs associated with generating systems involves, among other things, the construction of a model of the system capacity outages. This model is inherently discrete and application of the well-known and basic recursive technique requires lengthy computations when applied to large power systems. Alternatively, continuous distributions and fast Fourier transforms can be used to approximate the generating system capacity model. These techniques can in some cases introduce inaccuracies in the results, which depend on the system under consideration. Several authors have used these approximate techniques in the calculation of capacity outage probabilities, the study of parameter uncertainty in generating capacity reliability evaluation, the calculation of the expected energy production costs and the maintenance scheduling of generating facilities. This paper discusses the potential application of the approximate techniques in the evaluation of the marginal outage costs of a power system. The results of the approximate techniques are illustrated by comparison with those produced by the exact recursive technique for the IEEE-Reliability Test System     

Factors Affecting the Development of a Commercial Customer Damage Function

The assessment of reliability cost/reliability worth is an important aspect of power system planning and operation. Reliability cost evaluation has become a relatively well established procedure compared with reliability worth evaluation. This paper presents the results of an investigation of the effect of standby equipment on both the consumption and demand normalized outage costs in the commercial sector. The results of a comprehensive study to find the outage costs for respondents with and without standby systems, and the seasonal variation of these costs, are presented. The development of a localized customer damage function utilizing the data is explored.     

基于时间切片的供电可靠性影响分析

为支撑停电过程的供电可靠性提升决策,对预安排停电的供电可靠性影响特征进行了深入分析,通过停电标准作业环节的时间切片划分,为供电可靠性薄弱环节评价提供量化数据,通过研究影响供电可靠性指标变化的不利因素,辅助预安排停电过程精益化管控.     

复杂中压配电网开关优化配置数学模型及算例

配电网开关优化配置就是确定馈线上开关设备的最佳位置和数量,以提高系统可靠性,减少停电损失,提高资金的使用效率。本文介绍了开关优化配置中各种费用的计算方法,对现有的几种复杂中压配电网可靠性算法进行了比较和说明,并介绍了基于可靠性算法计算停电损失费用的方法。     

Outage costs quantification for benefit–cost analysis of distribution automation systems

Deregulation of electric power industry has motivated electricity customers to pay more attention in evaluating both the direct cost of electric service and the monetary value of reliable electric service. This movement has been recognized by the utilities and the value-based aspects are introduced into the planning and design of power systems to consider the outage costs. The value of service reliability that can portray and respond to actual utility and customer impacts as a result of power interruptions plays a major role on justifying whether a distribution automation (DA) system is beneficial or not. However, for the value of service reliability, there are a number of factors that can affect it. To exactly evaluate the service reliability value, two formulas for quantifying the customer interruption costs and utility reduced energy revenues associated with power failures are derived in this paper. The customer types, feeder loads, feeder failure rate, number of switch, restoration time, and repair time are taken into account. The proposed formulas can provide an exact estimate in outages costs of a feeder and their computation is simplified and straightforward. The estimated outage costs can then be used to calculate the reliability improvement benefit of DA systems for the system benefit–cost analysis. A practical DA system implemented by Taiwan Power Company is used to illustrate the proposed formulas and the benefit–cost analysis result is presented. Sensitivity analysis is also performed to reduce the effects of benefit–cost analysis parameters on the analysis result.     

The Application of Statistical Reliability Data in the Selection of a Utility Power Supply Scheme for an Industrial Plant

A detailed analysis was made to determine the most economical electrical utility supply configuration to serve a new polyester manufacturing facility. The basis used for the analysis centered around: a) IEEE survey reliability data and IEEE statistical reliability techniques, b) historical outage cost data from the three existing manufacturing facilities, and c) an estimated power restoration curve developed by the facilities maintenance department. Explicit definitions were developed to define what power outages meant for the various types of loads to be served. The minimum total yearly cost, made up of yearly facilities' cost plus yearly outage cost was used to identify the most economical configuration.     

Reliability centered planning for distributed generation considering wind power volatility

This paper investigates a stochastic planning model to minimize the lifecycle cost of distributed generation (DG) systems under the energy reliability criterion, namely the loss-of-load probability. In particular, our study focuses on the DG system penetrated by renewable wind technology. The optimization is formulated to determine the wind turbine capacity and their placement in the DG system with the intent to minimize the capital, operational and environmental costs. Statistical moments including mean and variance are utilized to characterize the wind power volatility and the load uncertainty. Genetic algorithm combined with heuristic search is used to find the best sitting and sizing of the distributed energy recourses. Our study is among the first attempts in the literature to model and optimize DG system based on continuous probabilistic theory. The moment methods are shown to be effective in characterizing the stochastic behavior of wind power and load dynamics. Case studies are provided to demonstrate the application and performance of the planning method.     

基于可靠性成本- 效益分析的电网规划

传统电网规划是以电网的直接投资费用最小为目标来满足一定可靠度的电网规划。电网规划的目的是保证电网的供电可靠性,而没有考虑由于电网的扩展所产生的经济效益,这样规划出的电网并不能获得最佳的社会效益。该文通过引入缺电成本,将可靠性与经济性结合在一起,在此基础上提出了一种新的电网规划成本-效益分析方法与数学模型,该方法将缺电成本作为供电总成本的重要组成部分,并且用缺电成本的大小来衡量可靠性效益的高低,将规划的可靠性成本与可靠性效益统一在对电网的经济性评估上。对规划方案进行了分析和评价,进一步完善了成本-效益分析方     

城市电网用户停电损失估算及评价方法研究

合理地估算和评价城市电网中各类用户的停电损失,为电力企业在提高城市电网的可靠性水平及应急电源优化配置的投资和决策方面提供依据。在对受停电影响造成的各类用户的经济损失进行分类调查的基础上,以峰荷时刻的停电损失为基准,建立了表示综合用户停电损失和停电持续时间关系的综合用户停电损失函数,用以估算每类用户的综合停电损失。基本计算过程为,根据各类用户的综合用户停电损失函数和停电次数的统计结果,采用停电损失评价率和每次事故停电损失2个指标来评价每类用户的停电损失。采用青岛地区53个重要用户的数据为实际算例,估算并评价了各类用户的停电损失。所得结果表明,所提出的估算和评价用户停电损失的方法,有助于电力企业确定不同可靠性水平下的应急电源优化配置成本。     

配电系统中变电站智能化升级策略

代表变电站技术发展趋势的智能变电站是智能电网的重要组成部分。智能变电站的配置对系统安全与经济运行具有重要影响,是值得研究的重要问题。在此背景下,研究了计及可靠性的配电系统中变电站智能化升级问题。首先,以变电站智能化升级成本和用户停电损失之和最小化为目标函数,考虑系统平均停电时间(system average interruption duration index,SAIDI)和电量不足平均值(average energy not supplied,AENS)这2个可靠性指标不超过给定阈值等约束条件,构建了配电系统中变电站的智能化升级优化模型。之后,发展了针对配电系统故障的故障清除模型,提出了评估用户停电时间的比较准确的方法。接着,对用户停电时间和用户停电损失函数进行线性化处理,得到变电站智能化升级问题的混合整数线性规划模型,并采用高效商业求解器求解。最后,以IEEE RBTS-Bus 4配电系统和丹麦某中压配电系统为例来说明所提方法的基本特征。