基于输电线路实时评估模型的电力系统静态安全在线风险评估

发布时间：2018-10-29 08:30

【摘要】：随着传统的电力系统静态安全分析方法的局限性和不足之处的日益暴露，人们逐渐地将研究重点转向不确定性分析方法。目前，不确定性分析方法中的随机潮流方法已经得到了比较深入的研究，但是从电力系统安全运行的角度将其应用于静态安全风险评估的研究却很少。针对电力系统传统的静态安全分析方法存在的缺陷，本文从风险的角度，对电网运行的安全性进行风险评估。本文对计及气象因素的输电线路故障概率的实时模型进行深入探讨，将输电线路分为绝缘子、导线、避雷器、杆塔、地线5个部分来进行在线监测，并依据其规格和实际运行情况分别建立了各个监测量的量化模型，然后采用未确知有理数的权系数法和模糊评估法，建立了基于在线监测数据的输电线路实时故障概率的层次评估模型，同时考虑当前的气象条件，建立了计及气象因素的输电线路故障概率的实时评估模型。本文深入探讨了可用于静态安全风险评估的随机潮流法。考虑了电力系统中存在的各种不确定性因素，并对负荷的波动性和发电机出力的随机性建立了相应的概率模型，，并提出了以半不变量为基础的Cornish-Fisher级数展开法进行随机潮流计算，对系统中由这些不确定因素造成的线路功率和节点电压的不确定性进行分析。本文从框架的观点提出了电力系统静态安全在线风险评估方法，并建立了适用于静态安全在线风险评估的风险指标。为了达到在线风险评估的实时性要求，本文根据提出的筛选指标对电力系统的预想故障集进行了实时故障筛选与排序；在此基础上，利用本文所提方法计算系统的综合风险指标，真实全面地反映系统在当前运行状态下所处的风险水平。
[Abstract]:With the limitation and deficiency of the traditional static security analysis method of power system, people gradually turn the research focus to the uncertainty analysis method. At present, the stochastic power flow method in the uncertainty analysis method has been deeply studied, but it is rarely applied to static security risk assessment from the point of view of safe operation of power system. Aiming at the shortcomings of the traditional static security analysis method of power system, this paper evaluates the security of power network operation from the risk point of view. In this paper, the real time model of transmission line failure probability considering meteorological factors is discussed in depth. The transmission line is divided into five parts: insulator, conductor, arrester, pole tower and ground wire. According to its specifications and actual operation, the quantitative models of each monitoring quantity are established, and then the weight coefficient method of unascertained rational number and the fuzzy evaluation method are adopted. Based on on-line monitoring data, a real-time fault probability evaluation model for transmission lines is established. Considering the current meteorological conditions, a real-time evaluation model of transmission line fault probability is established taking into account meteorological factors. This paper discusses the stochastic power flow method which can be used for static security risk assessment. Considering all kinds of uncertain factors in power system, the probability model of load fluctuation and generator output randomness is established. A Cornish-Fisher series expansion method based on semi-invariants is proposed to calculate the random power flow. The uncertainties of line power and node voltage caused by these uncertainties are analyzed. In this paper, an on-line risk assessment method for static security of power system is proposed from the viewpoint of frame, and a risk index suitable for online risk assessment of static security is established. In order to meet the real-time requirements of online risk assessment, this paper carries out real-time fault screening and sorting for the expected fault set of power system according to the proposed screening index. On this basis, the method proposed in this paper is used to calculate the comprehensive risk index of the system, which reflects the risk level of the system under the current running state.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TM711

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