基于可靠性的配电网用户停电损失估算方法研究

提出了一种综合用户停电损失函数和基于可靠性计算的用户停电损失估算方法。文章以用户调查方法为基础,获得峰荷状态下各类用户的停电损失,同时考虑各类用户的用电量比例和负荷率等因素,建立综合用户停电损失函数。根据元件在线路上不同位置对用户可靠性的影响,提出了用户停电损失的估算方法。该方法对工程人员进行电网规划和建设时的经济决策具有一定的参考作用。最后,以IEEE RBTS为例说明了该方法的可行性和有效性。     

基于熵权-灰色关联分析的降低区域停电损失举措研究

停电损失是衡量电网经济性标准之一,合理估算停电损失,能够为提高配电网可靠性和社会应急电源分配、公共预防性预算分配等提供依据。采用产电比法计算停电损失,并使用熵权加权计算各影响因素的客观权重,以提高灰色关联分析方法评价结果的准确性。使用熵权加权–灰色关联分析方法,分别计算区域产电比与各行业、配电网可靠性与其影响因素之间的关联度。在实际案例分析中,对4个不同区域的停电损失与各行业的紧密程度和区域配网可靠性与各影响因素之间的关系进行分析,从而提出每个区域电网设备升级的重点方向和地域,集中供电企业资金投入,最大限度提高配电网可靠性,降低停电损失。     

考虑综合负荷重要性的移动应急电源容量优化分配

研究了城市电网在固定的预算条件下,以大面积停电损失最小为目标,移动应急电源容量的优化配置问题。首先提出了将城市负荷分类统计,建立指标综合衡量停电损失的一种方法。然后依据该指标建立目标函数,在满足预算等条件下规划求解,得出将停电损失降为最低的移动应急电源数量及其在不同区域间的优化方案。     

基于分块技术的用户停电损失估算方法研究

介绍了停电损失的概念及影响因素．引入分块技术将配电网分块．并确定故障停电事件发生后各分块负荷点的类型;提出根据负荷点停电类型分别确认各分块区域的停电持续时间．结合综合用停电损失函数计算各分区的用户停电损失．最后汇总估算系统的用户停电损失．与传统的用户停电损失估算结果比较．证明了该方法的有效性。     

城市移动应急电源的优化调度

建设电力应急管理平台、建立和完善电力应急服务机制对提升电力系统应急保障能力意义重大。与此相关的一个重要问题是如何合理调度现有的移动应急电源,以提高城市电力系统应急处理能力进而最大限度地降低停电损失。现有电力应急方面的研究多侧重于应急指标体系的构建和应急平台的建设,而对于城市移动应急电源的优化调度研究还未涉及。在此背景下,构造了城市移动应急电源的双目标优化调度模型,以各失电用户总停电损失之和最小为主目标,以移动应急电源的富余容量最小为次目标。之后,针对该模型包含了非线性的最大值函数和符号函数而难以求解的问题,通过引入0-1变量等措施将原模型转化为混合整数线性规划问题,并提出了一种基于分层序列法的求解方法。最后,用算例说明了所提出模型和方法的基本特征。     

一种电力用户停电损失函数估算方法

电力用户停电损失函数对电力系统规划、运行和电力市场下的安全费用计算等具有重要意义。但求取停电损失函数需要区分不同电力用户的用电性质,也需要大量统计数据资料作为停电损失函数的分析依据,从而使其成为当前电力市场研究工作的一个难点。本文在目前研究成果的基础上,提出一种参考其它地区停电损失函数、根据所研究地区电力用户消耗每kW h电力的平均效益估算用户停电损失函数的方法。该方法避免了大量数据统计工作,对不同性质电力用户的停电损失函数进行快速简单分析。用加拿大停电损失函数近似估算了天津市电力用户停电损失函数,实例表明所提方法可行。     

一种电力用户停电损失函数估算方法

电力用户停电损失函数对电力系统规划、运行和电力市场下的安全费用计算等具有重要意义.但求取停电损失函数需要区分不同电力用户的用电性质,也需要大量统计数据资料作为停电损失函数的分析依据,从而使其成为当前电力市场研究工作的一个难点.本文在目前研究成果的基础上,提出一种参考其它地区停电损失函数、根据所研究地区电力用户消耗每kWh电力的平均效益估算用户停电损失函数的方法.该方法避免了大量数据统计工作,对不同性质电力用户的停电损失函数进行快速简单分析.用加拿大停电损失函数近似估算了天津市电力用户停电损失函数,实例表明所提方法可行.     

电网运行停电概率函数构建研究

提高供电可靠性,减少停电事件是电力企业的工作重点,也是电力用户的迫切希望。掌握电网运行停电事件的发生规律,可以为电力企业制定提高供电可靠性的有效措施提供依据。基于此,结合概率论理论,提出了构建电网运行停电概率函数的新方法。根据某地区2008—2010年的停电事件统计数据,运用Matlab软件建立了该地区电网运行停电概率函数,并对停电事件进行了分析,进而对该城市电网2010—2012年停电概率进行了预测。实例验证表明:该建模方法有效可行,可用于计算电网运行停电概率。本研究为评估电力用户停电损失做了前期准备。     

基于重要用户的应急电源优化配置

从各分区供电所应急电源的容量配置现状和重要用户的应急电源需求情况出发,充分考虑供电可靠性和企业经济性的关系,在一定的约束条件（时间约束、容量约束等）下,提出了以总费用最小化为目标的应急电源优化配置模型,建立了基于遗传算法的应急电源优化配置算法。通过算例分析和基于地理信息系统（GIS）的软件实现,验证了所提出的模型和算法的有效性。该研究有助于减少停电损失,提高城市电网的供电可靠性和应急能力。     

考虑时间分级的移动应急电源优化配置模型

合理配置移动应急电源对提高城市电网应急能力具有重要意义。综合考虑停电时间、用户自备电源供电时间、供应点与用户间交通时间、用户损失费用、应急电源投资和维护费用以及供应点交通便利度等因素,建立了含3个优化目标考虑时间分级的应急电源配置数学模型。提出了求解该模型的引入回溯表和长期表的多目标禁忌搜索算法;模型统一考虑了供应点选址及用户选择,并能够提供多种候选方案。实际算例证明模型和求解算法是合理和有效的,也有助于提高城市电网应急能力。     

Utilization of time varying event-based customer interruption cost load shedding schemes

Load curtailments occurring under emergency conditions can have significant monetary impacts on the system customers. Customer satisfaction is becoming increasingly important in the new deregulated electric utility environment, and the customers in some jurisdictions are beginning to receive monetary compensation for power supply failures. Minimizing the customer interruption costs associated with a load curtailment event is an important factor in maintaining customer satisfaction. Customer interruption costs depend on many factors such as the customer types interrupted, the actual load demand at the time of the outage, the duration of the outage, the time of day and the day in which the outage occurs. This paper focuses on incorporating these interruption cost factors in a load shedding strategy. The load shedding algorithm was developed using an approximate event-based customer interruption cost evaluation technique to identify and determine the priority of the distribution feeders on a given bus during an emergency. The developed algorithm incorporates a time dependent feeder cost priority index (FCP). The optimum load shedding set determined using the FCP is a feeder or group of feeders that meet a capacity deficiency, and result in the lowest customer interruption cost for the specified emergency situation. This paper illustrates the algorithm development for a load shedding scheme and demonstrates the utilization of the technique on a sample load bus.     

电力系统应急服务多点最优选址规划

合理规划电力系统应急服务点对于保证应急资源及时运送,进而降低停电损失具有重要意义。现有电力系统应急方面的研究多侧重于应急平台建设和相关指标体系构建,而对应急服务点选址优化问题则研究较少。在此背景下,通过综合考虑用户停电损失、停电时限约束及应急服务点的服务成本,建立了以电力应急总成本最小为优化目标的应急服务多点选址的优化模型,并采用Floyd算法求解该优化模型。最后,用算例说明了所构建模型的正确性与所采用算法的有效性。     

CDF-based Reliability Insurance Contracts Considering Free-riding

As a result of many disadvantages faced by the regulator in current regulatory schemes, reliability insurance scheme (RIS) has been introduced as a new regulatory scheme. This scheme allows consumers to determine their coverage levels according to their value for reliability services (i.e., cost incurred for outages), and pay corresponding premiums to the utility. The utility is then required to reimburse consumers for outages according to their outage cost. The consumer’s outage cost is extremely dependent on the duration of outages and this dependency is well defined by a function known as a Customer Damage Function (CDF). To enable consumers to fully cover the reliability risks, utility should provide consumers with contracts which allow them to select coverage levels according to their CDF.Due to the inflexibility of electrical grids, most utilities cannot differentiate the reliability services at the household level and so the public good aspects of the reliability services are emphasized. In such circumstances, selfish consumers can misrepresent their willingness to pay for the reliability services and benefit from their neighbors’ choices (i.e. free-ride on the reliable services provided for their neighbors). Free-riding may lead to the underinvestment in the grid. In this paper, primarily, CDF-based insurance contracts are designed and in following, a method for solving the free-riding problem is presented.     

Features that influence composite power system reliability worthassessment

Reliability worth assessment using customer interruption costs is an important element in electric power system planning and operation. This paper deals with two features that affect the composite generation-transmission system reliability worth assessment. One feature is the incorporation of temporal variations in the cost of interruption. This paper illustrates the effect on the expected annual system outage cost of temporal variation in the interruption costs for the residential, agricultural, industrial, commercial and large user sectors. The other aspect considered in this paper is using a probability distribution approach to represent the cost of interruption model. The conventional customer damage function approach utilizes average customer costs while the probability distribution approach recognizes the dispersed nature of the customer outage data. These two methods of cost evaluation are applied to reliability worth assessment in this paper. A sequential Monte Carlo approach incorporating time varying loads is used to conduct all the studies. Case studies performed on two composite test systems show that incorporating time varying costs of interruption for the industrial sector resulted in a significant reduction in the expected outage cost. A comparison of the reliability worth obtained using the customer damage function method (CDF) with the probability distribution approach suggests that using the CDF method may significantly undervalue the reliability worth by a factor of three to four     

Value of service reliability

The authors present the value of service (VOS) reliability evaluation approach, which explicitly incorporates into the planning process customer choices regarding reliability `worth' and service costs. Using the least-cost planning framework and taking advantage of the recent advances in the quantification of outage costs, this approach determines the optimal level of reliability for the utility and its customers. The approach considers system operational measures-the so-called emergency actions-that the operators invoke in times of dwindling reserves. Information on customer outage costs associated with such actions is incorporated using a probabilistic framework. This approach permits utilities to plan for levels of reliability commensurate with the customers' willingness to pay. The application of this methodology to planning problems is discussed. Numerical results for a large utility are presented     

基于鲁棒模型预测控制的配电网供电恢复策略

随着微网技术的发展,配电网发生故障后,利用配电网中的微网为停电负荷提供应急供电,可以减小配电网停电范围,提高配电网的弹性.由于微网内可再生能源出力和负荷需求存在不确定性,现有研究主要采用单时步随机优化方法生成供电恢复策略.然而,由于准确的概率分布模型较难获得,且单时步优化方法仅优化未来一个时间段的运行方案,忽略了多个时间段中状态的相关性,降低了运行的效率.为此,文中提出了基于鲁棒模型预测控制的弹性运行策略.首先,以每个控制周期内多个时步的成本最低为优化目标,建立了基于鲁棒模型预测控制的优化决策模型.由于该模型是min-max问题,难以直接求解,可采用强对偶理论将其转换为单层混合整数模型.最后,采用IEEE 69节点配电系统对所提方法的有效性进行了验证.     

基于物元分析理论的大电力客户信用评价

分析、评估及掌握电力客户用电行为,是电力企业营销活动的重点和难点。笔者在分析电力市场环境、客户纳费态度及能力等因素的基础上,构建电力客户信用等级评价指标体系,并将物元分析理论引入电力客户信用评价中,构建电力客户信用评价的物元分析模型,针对电力客户信用评价的复杂性以及单因素识别和等级划分之间不一致的特点,应用物元可拓集方法构造物元矩阵,根据计算出的关联度大小对电力客户信用等级进行可拓识别。实证结果表明:将物元分析法用于电力客户信用评价,评价结果更加客观、合理。     

基于恢复价值动态评估的配电网恢复控制决策

配电网停电后,停电场景、恢复进程和应急情况下的负荷职能等均会影响负荷恢复供电的紧急程度,通常根据待恢复对象自身的恢复价值静态设置其重要等级或重要度,这制约了有限恢复资源的精细化管理.为此,考虑冷负荷启动特性与负荷间职能耦合关系对负荷单位恢复价值的影响,考虑间歇性电源出力的可控性对电源恢复价值的影响,结合母线恢复为周边其他待恢复对象带来的潜在恢复价值,同时计及系统供电缺额、恢复代价和恢复操作的不确定性,提出了综合恢复收益、代价和风险的负荷及电源母线恢复价值动态评估方法.以此为基础,建立了配电网供电恢复多进程优化模型及分区并行恢复决策方法.最后,通过仿真分析验证了所提策略能够有效提高恢复资源的利用率.     

基于V2G技术的城市电网供电恢复策略

随着电动汽车的大量推广,城市电网中的电动汽车总容量逐渐增加,基于电动汽车入网(V2G)技术,考虑电动汽车的放电能力,将其作为辅助电源配合应急供电车可快速恢复失电负荷,在有效降低失电损失的同时,具有灵活性好、能降低应急储能和应急供电车等传统应急能源的配置成本等优点。建立了电动汽车的放电模型,以此评估可供调配电动汽车电池的电源水平;将失电负荷的重要度、容量等因素作为有限电源分配的依据,以最小化负荷失电损失为目标,结合遗传算法和改进鲸鱼算法进行求解,提出了基于V2G技术的供电恢复优化策略。算例仿真结果验证了所提方法的可行性和优越性,可为未来电动汽车大规模接入后城市电网的供电恢复策略研究提供新的思路。     

一种新的气体绝缘电气设备

当前电网中引入了许多基于AIS和GIS技术组合的新型高压开关装置,行内称之为HGIS。因其尺寸更小、更环保、成本更低、安装时间更短、停电时间更少,供电企业已经开始用这类新型高压组舍电器来取代传统敞开式变电站设备。这些开关装置可以大幅度提高电网的运行可靠性,逐步减低设备的寿命周期成本,提升供电企业的劳动效率。