【作者】 袁明军；

【导师】 刘玉田；

【作者基本信息】 山东大学 ， 电力系统及其自动化， 2011， 博士

【摘要】 配电系统将输变电系统与用户连接起来,向用户分配和供应电能,包括配电变电站、高低压配电线路、馈线等网络和设备。作为直接与用户相连的部分,配电系统直接影响着用户正常供电,其在安全、可靠以及经济供电方面发挥着重要作用。随着社会的发展和经济结构的调整,信息工业等对供电要求更高的产业比重越来越大,用户对供电可靠性的要求越来越高,如何向用户提供高可靠性的电力是电力工作者不容回避的现实,也是电力系统发展的必然要求。低压用户供电可靠性是反映电力企业供电能力和供电质量的最主要指标之一,是供电系统的规划、设计、设备选型、施工、生产、运行及供电服务等方面水平的综合体现。开展低压用户供电可靠性统计工作最大难点在于低压用户的数量众多和分布广泛,其基础数据量很大且运行数据难以全面采集。探索一种既可以有效统计低压用户供电可靠性、投资又可接受的方法,为整个配电系统可靠性与经济性的评估提供依据,具有重要理论意义和实用价值。与发电和输电系统研究相比,配电系统可靠性研究起步较晚。由于缺乏必要的统计数据和行之有效的分析方法,发展较为缓慢。近年来,随着国民经济的飞速发展,城市用电负荷迅速增长,供需矛盾日益突出,配电可靠性在生产管理工作中所占的位置也越来越重要。为使有限的资源取得最大的收益,迫切需要对配电系统进行科学合理的规划,从而促进配电系统供电可靠性评估的发展。绝大多数电力系统输变电设备都暴露于外部气候条件下,主设备易受气象事件影响是电力系统运行的重要特征之一。大气湿度、污浊程度、大风、冰雪冻雨、雷暴、大雾等偶发性气象事件都会影响到元件的故障率；严重气候事件会导致聚集性故障,严重影响系统的可靠性水平。研究大风等气候条件对高压配电系统可靠性影响的模拟方法,有助于深入理解不利气候条件下聚集性故障对系统可靠性的影响,从而从微观、细粒度层面揭示气候的作用,具有重要理论意义。本文围绕低压用户供电系统可靠性评估方法与应用、基于成功概率的配电系统可靠性评估方法、考虑大风气候影响的高压配电系统可靠性评估等内容,从多个层面对配电系统可靠性进行了深入研究,并将部分成果应用于多家电力公司。主要工作和取得的成果如下：(1)低压用户供电系统可靠性评估方法与应用提出了基于概率统计模型检验的低压用户供电系统可靠性统计评价方案,开发了相关软件系统,并应用于实际电网。根据概率统计理论的计算分析结果,在统计范围内按测量精度要求设置相应的低压用户供电可靠性监测点,将监测点采集的运行数据传输到计算分析中心,实现指标的自动计算分析。该方案有效克服了目前我国低压用户供电可靠性统计投资大、统计结果误差大的问题。开发了低压用户可靠性评估仿真模拟系统,可用于校核所采用评估方法的有效性,对提高配电系统可靠性评估管理水平、改进可靠性评估精度具有重要作用。在多家电力公司的应用取得了良好效果。(2)基于成功概率的配电系统可靠性评估方法如何提高配电系统供电可靠性并尽可能降低投资是电力系统的一个重要课题。在分析一些常用的配电系统可靠性评估方法的基础上,引入元件平均成功运行概率的概念,提出了一种基于成功概率的配电系统可靠性评估方法。该可靠性评估方法不会因为配网分支馈线的增多而变得复杂,在对网络进行拓扑分析的基础上只需要一次遍历,即可同时得到负荷点的故障率和成功运行概率,进而可直接得到负荷点的故障持续时间。其优点在于故障率和成功运行概率并行计算,且网络模型不会因为分支馈线的增多而变得复杂,可以通过简单的加法和乘法运算即可快速准确地得到可靠性指标,具有原理清晰、编程简单、结果准确、计算快速等特点。(3)考虑大风气候的高压配电系统可靠性评估方法分析了气候条件对配电系统可靠性影响的规律和研究现状,针对大风不利气候条件影响电网的特征,提出了大风不利气候对高压配电系统可靠性影响的模拟方法,基于蒙特卡罗抽样原理随机产生故障场景,并通过详细的时域仿真工具进行分析计算。该方法能够模拟大风天气下聚集性故障特征,并弥补了仅从静态、宏观层面进行可靠性分析的不足。开发了考虑大风气候的高压配电系统可靠性评估系统,针对山东电网实际规划数据,进行了大量仿真,分析了系统在给定外部大风条件下的可靠性。算例仿真表明系统能够处理实际电网数据,给出量化可靠性评价指标；大量的模拟抽样仿真可以揭示电网结构的潜在问题,为电网规划提供参考。更多还原

【Abstract】 Distribution system, linking transmission system and users together, distributes and supplies electricity to users. It includes distribution substation, high and low voltage distribution lines, feeder lines and other networks as well as devices. As a part connected directly to users, the reliability of distribution system directly affects the normal power users. Therefore, it plays an important role in the safety, reliability and economy of power supply. With the restructuring of economy and growing proportion of demanding industries such as information industry, security requirement of users becomes higher and higher. How to supply users with high-safety electricity is an unavoidable reality of electricity workers, and a necessary requirement for the development of power systems.The power supply reliability of low-voltage users is one of the main indexes that reflect the ability and quality of power supply utilities. It embodies the comprehensive level of power system in terms of plan, design, device selection, construction, production, operation and service. However, it is difficult to get the statistic reliability of low-voltage users, because such users are numerous and widely distributed, which means the basic data is too large and operating data is hard to collect. Therefore, exploring an investable method that can calculate the statistical reliability of low-voltage users and provide the basis for evaluation of the entire distribution system reliability and economy has important theoretical significance and value.Comparing to generation and transmission system, the study of distribution system reliability started late. Due to lack of necessary statistical data and effectively analytical method, development was relatively slow. In recent years, with the rapid development of the national economy, the urban power load has been increasing quickly so that the conflict between supply and demand has become very prominent. Consequently, the reliability of power distribution has been becoming more and more significant in producing management. In order to achieve maximum benefit based on limited resource, we urgently need a kind of scientific and rational plan of distribution system, which will contribute to the development of reliability assessment of distribution system.Most power transmission and transforming equipments are exposed to external environment. In addition, the main equipments are susceptible to weather events, which is an important feature of power system. Atmospheric humidity, pollution level, strong wind, snow as well as ice rain, thunderstorms, fog and other occasional weather events will affect the fault rate of components; severe weather events may even lead to a cluster of failures, seriously affecting the level of system reliability. Studying the method that can simulate the effect of strong wind and other climatic conditions on the reliability of high-voltage distribution system will contribute to a better understanding of faults aggregation under extreme weather conditions, and then it becomes possible to reveal the role of climate from a micro, fine-grained level, which has theoretical significance.Focusing on assessment method of low-voltage power system reliability, new evaluation method of system as well as distribution network reliability, and assessment of high-voltage distribution system reliability considering the effect of strong wind, this dissertation studies the reliability of power distribution in detail, mainly including:(1) Reliability assessment method and application of low-voltage power supply systemsA statistical evaluation scheme of power supply reliability of low-voltage users based on a test of probabilistic and statistical model is proposed, and relative software is developed and applied to actual power system. According to the calculation as well as analysis results of probabilistic and statistical theory, and precision requirements within the statistical range, corresponding reliability monitoring points of low-voltage users are set. Then operating data collected from monitoring points are transferred to a computer center, which calculates and analyzes indexes automatically. This scheme effectively overcomes the problem that the investment of reliability statistics of low-voltage users in China and the problem that statistics results have big errors.(2) Reliability assessment method of distribution system based on success probabilityHow to improve the distribution network reliability and minimize the investment is an important topic in modern power system operation and control. With reviewing some general used reliability assessment methods of distribution system, by introducing the concept of average success operating probability of component, a new method is proposed based on success probability. The method will not become more complex with the number of branch feeder lines increasing. Therefore, based on the network topology analysis, only one traversal is required, and then the fault rate as well as success operating probability of a load point can be obtained. Further, the fault duration can be determined. This method has several advantages. The failure rate and success operating probability can be calculated in parallel; the network model will not become more complex when the number of branch feeder lines increases; the reliability index can be obtained quickly and accurately by simple calculations such as addition and multiplication; it has clear principles, accurate results, fast computation and can be programmed easily. (3) Reliability assessment of high-voltage distribution network considering windy climateThe principle and research status of the effect of climate on distribution network reliability are analyzed. According to the features of the impact of windy climate on the grid, a numerical simulation method of the effect of windy climate on power system is proposed. It generates random failure scenarios by Monte-carlo simulation method, carries out analysis and calculation through a detailed time-domain simulation tool. The proposed method can simulate the characteristics of fault aggregation under windy climate, which makes up the shortcoming caused by analyzing only from the steady-state view. A reliability evaluation system for high-voltage distribution system considering the windy climate is developed. Based on the actual data of Shandong power grid, a large number of simulations and reliability analysises have been done under the condition of a given external wind. Example simulations show that the system can handle actual grid data. A large number of analog sampling simulations can reveal potential problems, and provide the reliability level of system under the condition of fault aggregation.更多还原