计及不同灾害条件下杆塔可靠度的电网可靠性评估研究

发布时间：2018-02-15 22:20

本文关键词： 杆塔可靠度当量正态化法窄界限法混合抽样策略改进状态空间分割法可靠性评估　出处：《浙江大学》2017年硕士论文　论文类型：学位论文

【摘要】：伴随着国民经济体量的增加,电力系统的规模相应扩大,其故障带来的经济损失和社会影响不断增加,其安全稳定运行的重要性也显著提升。近年来,多起自然灾害使电网遭受了严峻的考验,例如我国南方部分地区在2008年发生了持续时间长、强度高的大规模冰冻灾害天气,致使当地发生多起输电杆塔倒塔断线事故。输电杆塔是输电线路的基础支撑结构之一,其可靠度将对线路及全网的可靠性产生直接影响。因此,对计及不同灾害条件下杆塔可靠度的电网可靠性评估的研究至关重要。首先,以浙江省某地实际气候统计数据为参考,设定不同气候条件,对输电杆塔荷载效应、荷载效应比、荷载计算、杆塔构件功能函数、基本随机变量统计参数等进行研究,建立基于JC法与窄界限法的杆塔可靠度模型,计算不同气候条件下杆塔体系可靠度和失效概率。算例结果表明,该模型能准确评估塔体系可靠度和失效概率。然后,针对蒙特卡洛模拟法无法兼顾计算时间和计算精度的缺陷,为了提高电网可靠性评估抽样方法的抽样效率,对系统状态空间分割法、系统状态快速排序技术、重要抽样法和拉丁超立方抽样法进行研究,建立高效的基于混合抽样策略的改进SSP电网可靠性评估模型。运用该模型把待评估系统进行状态空间分割,得到子空间SF和SM,分别用解析法和重要-拉丁超立方抽样法对其进行分析。算例结果表明,本文所提模型是一种高效、准确的评估模型。最后,设定待评估系统受不同气候条件影响的区域和受影响程度,结合上述模型,计算杆塔体系失效概率,做出适当简化,假设线路为由若干杆塔体系组成的串联体系,并由此计算线路故障率,运用基于混合抽样策略的改进SSP电网可靠性评估模型对系统进行可靠性评估。算例结果表明,该方法能够快速、准确地评估电网受不同气候条件影响时的可靠性。
[Abstract]:With the increase of the national economy, the scale of the power system expands accordingly, the economic loss and social impact caused by the failure increase continuously, and the importance of the safe and stable operation of the power system increases significantly in recent years. Many natural disasters have put the power grid to a severe test. For example, in 2008, some parts of southern China experienced large-scale frozen weather with long duration and high intensity. The transmission tower is one of the basic supporting structures of the transmission line, and its reliability will have a direct impact on the reliability of the transmission line and the whole network. It is very important to study the reliability evaluation of power grid considering the reliability of the tower under different disaster conditions. Firstly, taking the actual climate statistics data of a certain place in Zhejiang Province as a reference, the load effect and load effect ratio of transmission tower are set up under different climatic conditions. The reliability model of the tower based on JC method and narrow limit method is established by studying the load calculation, the function function of the tower members and the statistical parameters of the basic random variables. The reliability and failure probability of tower system under different climatic conditions are calculated. The results show that the model can accurately evaluate the reliability and failure probability of tower system. In order to improve the sampling efficiency of the sampling method for reliability evaluation of power network, the system state space segmentation method and the system state rapid sorting technique are proposed in order to improve the sampling efficiency of the Monte Carlo simulation method, which can not take into account the calculation time and accuracy. The important sampling method and Latin hypercube sampling method are studied to establish an efficient reliability evaluation model for improved SSP power network based on mixed sampling strategy. The model is used to partition the state space of the system to be evaluated. The subspace SF and SMare analyzed by analytic method and important Latin hypercube sampling method respectively. The numerical results show that the proposed model is an efficient and accurate evaluation model. According to the above model, the failure probability of the tower system is calculated and simplified, assuming that the line is a series system composed of several tower systems. The reliability evaluation model of improved SSP power network based on mixed sampling strategy is used to evaluate the reliability of the system. The results show that the proposed method can be used to evaluate the reliability of the system quickly. Accurately assess the reliability of the grid under different climatic conditions.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM732

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