计及分布式电源的配电网风险评估研究

发布时间：2018-07-13 07:38

【摘要】：配电网是电力系统中直接与用户连接的部分，承担着向用户提供稳定、可靠、优质电能的重大责任。据统计，电力系统中80%的用户停电事件是由配电网故障引起的，这些突发的停电事件给国民经济和人民生活带来了重大损失。因此，加强对配电网的风险评估和管理，努力提高供电连续性和供电质量在我国是一项严峻而富有重要意义的工作。随着智能电网的发展，分布式发电技术的引入一方面缩短故障后配电网恢复对负荷供电的时间，减少停电损失；另一方面配电网结构的改变和分布式电源输出的间歇性和随机性，又使得配电网的风险分析模型和评估方法发生了重大改变。本文针对含分布式电源的配电网停电风险评估方法及停电风险控制方法进行研究，主要工作如下： ①针对分布式电源接入配电网后对配电网故障期间运行方式的影响，提出在传统配电网风险评估流程中加入孤岛划分，，并且为了减少孤岛划分的计算时间、提高风险评估的评估速度，通过定义负荷点的贡献度与消耗度两个孤岛划分参量，削弱了孤岛划分算法中负荷点接线结构对算法快速性的影响，以此提出了一种既满足评估精度、又能有效减少孤岛算法时间的快速孤岛划分方法。 ②针对含分布式电源的配电网停电风险评估对计算快速性要求的提升，在总结了现今常用的风险评估方法的基础上，本文提出采用方差更小、收敛更快的拉丁超立方分布-蒙特卡罗抽样方法对系统状态进行抽样，通过对配电网系统变量实施分区、抽样、排序的方式得到用于停电风险评估的系统状态；并且从供电充裕性角度建立了配电网停电风险的指标体系，以此制定了相应的停电风险评价标准。 ③针对传统配电网风险研究的对象只仅仅是对配电网的识别和估测，而缺乏相应的以降低配电网风险为目的的风险控制方法研究的问题，本文提出了基于改进遗传算法的含DG配电网停电风险控制策略，该策略能够在识别出配电网潜在的停电风险后通过线路维修与更换决策的优化提供综合效益最优的配电网停电风险控制方案。本文分析了基于线路维修与更换的风险控制经济性指标，建立了含DG配电网的风险控制模型；利用基于小生境技术的自适应遗传算法对风险控制模型进行求解。
[Abstract]:Distribution network is a part of power system which is connected with customers directly. It bears the great responsibility of providing stable, reliable and high quality electric energy to users. According to statistics, 80% of the power system power outages are caused by distribution network failures, these sudden power outages have brought great losses to the national economy and people's lives. Therefore, strengthening the risk assessment and management of distribution network and striving to improve the continuity and quality of power supply is a serious and important work in China. With the development of smart grid, the introduction of distributed generation technology on the one hand shortens the time of restoration of distribution network to load after failure, and reduces the loss of power cut. On the other hand, the change of distribution network structure and the intermittent and randomness of distributed generation output make the risk analysis model and evaluation method of distribution network changed greatly. In this paper, the risk assessment method of distribution network blackout and the control method of power outage risk are studied. The main work is as follows: 1 in view of the influence of distributed generation on the operation mode of distribution network during the fault period, the paper proposes to add islanding into the traditional distribution network risk assessment process. In order to reduce the calculation time of islanding and improve the evaluation speed of risk assessment, two islanding parameters are defined by defining the contribution degree and consumption degree of load point. The influence of load point connection structure on the algorithm's rapidity is weakened in the islanding algorithm, and a new method is proposed to satisfy the accuracy of evaluation. The fast islanding method can effectively reduce the time of islanding algorithm. (2) aiming at the improvement of the calculation speed of power outage risk assessment in distribution network with distributed generation, this paper summarizes the commonly used risk assessment methods. In this paper, a Latin hypercube distribution-Monte Carlo sampling method with smaller variance and faster convergence is proposed to sample the system state. The system state of power failure risk assessment is obtained by ranking method, and the index system of distribution network blackout risk is established from the point of view of power supply adequacy. Based on this, the corresponding evaluation criteria of blackout risk are established. 3 the research object of traditional distribution network risk research is only the identification and estimation of distribution network. However, there is no corresponding risk control method to reduce the risk of distribution network. In this paper, an improved genetic algorithm is proposed to control the risk of power failure in distribution network with DG. After identifying the potential blackout risk of distribution network, the strategy can provide the optimal control scheme of power outage risk through the optimization of line maintenance and replacement decision. In this paper, the economic index of risk control based on line maintenance and replacement is analyzed, and the risk control model with DG distribution network is established, and the adaptive genetic algorithm based on niche technology is used to solve the risk control model.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM732

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