配电网可靠性分层评估算法

针对故障产生的三种模式,分析了故障的三种模式对配电网可靠性的影响,提出了一种基于故障扩散的电网可靠性评估算法。该算法可快速计算电网各馈线、变电站和电网的可靠性指标,并可找出影响供电可靠率的薄弱环节,为配电系统规划和管理及城乡电网改造提供了有力的分析工具。同时对算例进行了验证,计算结果表明了算法的有效性。     

一种基于半马尔柯夫过程的配电系统可靠性经济评估方法

针对配电系统故障时间分布不确定的特点,提出了基于半马尔柯夫过程的可靠性经济评估通用方法。建立元件寿命、预防维修时间和修理时间服从任意分布的可靠性评估模型,引入用户停电损失函数研究系统在不完善预防维修情况下的停电损失;通过实例证明了该方法的正确性,显示出该方法对Homogenous M arkov和W e ibu llM arkov算法的兼容性、有效性,同时更清晰地反映了元件故障持续时间分布对系统可靠性经济指标的影响。     

Asset maintenance planning in electric power distribution network using statistical analysis of outage data

The problems faced by electric power utilities in developing countries today is that the power demand is increasing rapidly whereas the supply growth is constrained by aging generating and distributing assets, scarce resources for constructing new ones and other societal issues. This has resulted in the need for constructing new additional generating plants and a more economic ways of planning and maintaining existing Generating and Electric power distribution assets. System planning and maintenance that is based on reliability – centred asset management approach had been adopted in this paper.Maintenance of critical asset is an essential part of asset management in distribution network. In most Electric utilities, planning for maintenance constitutes an essential parts of asset management. In this paper, an enhanced RCM methodology that is based on a quantitative statistical analysis of outage data Performed at system/component level for overall system reliability was applied for the identification of distribution components critical to system reliability. The conclusion from this study shows that it is beneficial to base asset maintenance management decisions on processed, analyzed and tested outage data.     

配电系统可靠性评估方法及影响因素

针对配电系统可靠性评估问题,提出了一种网络等值-最小割集法的配电系统可靠性评估方法,该方法适用于复杂配电网,既能计及配电网实际面临的计划检修等问题对可靠性评估的影响,又可以保证可靠性计算的速度与精度.使用该方法研究了分布式电源的接入位置对配电系统可靠性的影响,指出在连接支路最多的节点处装设分布式电源效果是最好的.     

基于ZABBIX的自动化巡检系统的研究与实现

为了实现信息系统的自动化巡检，文章分析论述了信息系统运维巡检工作的现状，并提出通过开源实时监控工具ZABBIX提取信息系统基础资源指标，在此基础上研究出一套自动化巡检系统，实现基础资源管理、信息指标管理以及巡检业务的自动化，以此改善资源调配，增强数据可靠性，提高工作效率。从而提升运维工作自动化水平。     

配电系统可靠性评估的改进区间分析方法

提出了一系列区间计算的反演公式，建立了基于Markov过程的区间可靠性分析模型，实现了配电系统可靠性的改进区间分析方法及软件。配电系统可靠性区间算法可以同时考虑所有元件可靠性参数的不确定性所带来的影响，只需要1次计算即可求解反映参数变化影响的区间可靠性指标；同时，该算法也可作为一种全新的灵敏度算法。该算法在计算速度上优于Monte Carlo法，在灵活性和所提供可靠性指标的信息量上优于传统解析法。     

基于气候因素的配电网络维修风险管理

配电系统处于电力系统的末端,直接与用户相连,是整个电力系统与用户联系的纽带,是向用户供应电能和分配电能的重要环节。气候因素对配电线路的失效率影响较大,因此,管理配电线路维修期计划应考虑气候因素的影响。基于此,建立了考虑气候因素的配电线路维修风险分析方法,对不同气候条件下的配电线路维修风险水平进行了量化的期望缺供电量比较,为配电线路维修风险管理提供科学的依据。     

基于Semi-Markov的配电可靠性成本估计

针对配电系统故障时间分布不确定的特点,提出了基于半马尔柯夫过程的可靠性成本评估通用方法。建立元件寿命、预防维修时间和修理时间服从任意分布的可靠性评估模型,引入用户停电损失函数研究系统在不完善预防维修情况下的停电损失;通过实例证明了该方法的正确性,显示出该方法对Homogenous Markov和Weibull Markov算法的兼容性、有效性,同时更清晰地反映了元件故障持续时间分布对系统可靠性经济指标的影响。     

Impact of supply restoration procedures on the reliability performance of power distribution systems

The purpose of this paper is to describe an efficient computational methodology that models supply restoration procedures, which are available in power distribution systems, and calculates their impact on the reliability performance of system load-points. This methodology recognizes various practical operating features of the distribution systems under consideration and deduces the switching operations that are available to be executed, following the occurrence of a failure event. A set of five probabilistic indices is also obtained for each affected load-point taking into account the component reliability parameters and the system operational and maintenance practices being applied. The unavailability indices of the system standby components are calculated separately and their effect on the system reliability performance is established. Finally, the analysis of a typical 150 kV/20 kV system based on a real Greek urban distribution system is included.     

基于泛在电力物联网的电动汽车充电站运维关键技术

当前电动汽车快速发展,针对电动汽车充电站运维工作中存在的不足,以电动汽车应用为信息架构,提出一种基于泛在电力物联网的充电站运维策略制定方法。根据充电站的设备结构与运行特性,建立关键充电设施故障模型;以充电过程耗费的额外时间为风险指标,对电动汽车充电站进行可靠性分析,并依据风险值对不同站进行重要度等级划分,制定运维策略。以某市的一个区域为例,通过实时设备故障模型和用户充电模型对各充电站进行可靠性评估并合理分配运维时间和运维资源。     

Modeling failure data of overhead distribution systems

An overhead power line can be regarded as a collection of components each of which contribute in a particular way to its reliability. An overhead distribution system is a collection of such lines. A repairable system is a system which after failing, can be restored to an operational, but not a new state by repairing or replacing one or more components. This work treats the distribution system as a holistic entity with the aim of measuring the pattern of failures as an indication of reliability growth or deterioration. Comparison is made using case studies of an urban and a rural system based on trend analysis, the Laplace statistic and confidence limits. It is argued that although the pattern of failure of a distribution system may emulate a stationary point process, this can be misleading in the assessment of reliability and the impact of maintenance policies     

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     

Value-based distribution reliability assessment and planning

This paper presents a reliability assessment method for radial distribution systems. It combines, the radial network reliability and the customer interruption costs to form the Value-Based Distribution Reliability Assessment (VBDRA) methodology, which is a valuable tool for distribution system planning incorporating customer interruption costs. The proposed method is implemented in a Lotus 1-2-3 macro program with a specially designed data structure for the radial network. The analysis of the proposed computational method shows that the method is valid and fast in practical applications. Various applications of VBDRA planning at the Scarborough Public Utilities are reported in the paper     

Active correlation technology applied to maintenance program based on voltage sags control

This paper presents an Active Correlation Technology (ACT) for voltage sag detection and control. ACT is a conceptual architecture developed by IBM and can be successfully implemented to manage maintenance activities of distribution networks. As an instrument, maintenance clearly impacts on system reliability and quality of supply, i.e., very limited maintenance will result in an excessive number of costly failures and poor system performance, and therefore, reliability and quality of supply are degraded; done often, both reliability and quality of supply may improve but the cost of maintenance will sharply increase. Efficient maintenance schemes consider condition monitoring and maintenance activities are performed when a threshold pattern is violated. In this paper, a correlation engine is proposed to set voltage sag threshold patterns to detect abnormal sag incidence on MV feeders and trigger alarms to indicate the need for maintenance activities. The central ideas are validated with records obtained from a medium voltage circuit operated by one of the distribution divisions of the Mexican utility.     

Leveling reliability in systems with large hydro resources

Reliability analysis of a generating system is established in terms of the reliability characteristics of the different units in the system and in terms of the demand of energy to be satisfied. When the analysis is performed for the long-term (one year or more duration periods), the maintenance needs of thermal units as well as the time distribution of resources for units with energy restrictions, must also be taken into account. This paper describes a method for determining the optimal strategy for allocating the yearly energy resulting from random water inflows to the different subperiods of a year so that the reliability for all the subperiods is leveled. A characteristic feature of the method is that the uncertainty inherent in forecasting future available hydroenergy is transferred to the reliability index. The procedure is illustrated by an example prepared using the Spanish generating system     

配电网全寿命周期可靠性评估和管理问题研究

在配电网的规划过程中,因为缺乏统计数据只能进行理论可靠性的计算和评估,但现有的可靠性评估指标显得比较粗旷、且没有针对性,不能很好地体现不同业务范畴(规划、维护和运行)内的可靠性管理问题。文章基于理论可靠性评估的优化模型提出了全寿命周期可靠性的概念以及指标体系。基于全寿命周期可靠性概念,提出通过效益成本比来优选可靠性提升项目,并将可靠性目标分解到个业务范畴以精细化可靠性管理。以沿海某城市为例,演示了文中提出的全寿命周期可靠性管理方法的可行性,总结了该方法的优缺点。     

计及可靠性约束的配电网故障指示器优化布点方法

近年来,故障指示器凭借其接入灵活性和经济性被广泛应用于配电网故障定位中。然而全覆盖式地故障指示器安装配置方案投资成本高,规划方案不精益。文中提出一种基于故障信息变量的配电网可靠性评估模型;进一步给出一种基于混合整数线性规划的可靠性约束的配电网故障指示器优化布点方法,将可靠性指标作为约束放入优化模型中,在满足可靠性要求的前提下降低故障指示器的投资维护成本。基于IEEE 53节点系统的算例仿真结果表明,所提方法兼顾了故障指示器布点的可靠性与经济性,可以精确获得不同可靠性要求下的布点方案。     

基于电动汽车的极端场景多微电网韧性提升策略研究

极端场景下微电网与主网断开形成多个孤岛时,微电网内重要负荷的持续可靠供电面临极大挑战。微电网群内的电动汽车储能参与负荷支撑是提高系统韧性的有效技术手段。针对微电网孤岛供电问题,提出了一种基于电动汽车储能的多微电网两阶段韧性提升策略。首先,建立正常运行时多微电网能量管理模型,通过协调系统内各类发电资源进行能量互济,实现运行成本最小化。然后,针对台风极端事件引起的孤岛微电网持续可靠供电问题,通过多微电网各类发电资源和电动汽车储能进行能量互济,构建了多微电网两阶段韧性提升模型,最大限度地减少切负荷量,使系统运行成本最优。最后,采用Shapley值对涌现收益进行合理分配,并通过与传统多微电网能量管理方法进行对比,验证了所提韧性提升策略的有效性。     

考虑可靠性成本的配电网多阶段扩展规划方法

传统的配电网可靠性评估通过模拟组件中断来量化一组事件对供电可靠性的影响,这种基于模拟的可靠性评估方法使得其纳入到配电网扩展规划中需要采用启发式或元启发式方法求解。为了克服启发式或元启发式方法收敛性和局部最优的缺点,文中提出了考虑可靠性成本的配电网多阶段扩展规划的混合整数线性优化模型。该模型建立了配电网可靠性指标(即系统平均停电持续时间指标、系统平均停电频率指标和系统缺供电量)的显式评估表达式,并将其相关的可靠性成本纳入到配电网多级扩展规划目标函数中,以系统运行约束等为约束条件。在24节点、54节点、86节点和138节点四个算例系统上验证了所提出的方法的有效性和适用性。     

配电网可靠性指标的灰色组合预测方法及应用

针对配电网可靠性的特点,在充分考虑可靠性指标的历史变化趋势和顾及各种相关因素对可靠性指标的影响的情况下,分别建立了基于历史统计数据的横向预测模型和考虑相关因素影响的纵向预测模型,形成了灰色组合预测模型,充分发挥了灰色预测模型所需样本小、精确度高的优点.对某地区配电网可靠性统计数据的实例分析,证明了该方法的有效性.