【作者】 刘道兵；

【导师】 顾雪平；

【作者基本信息】 华北电力大学 ， 电力系统及其自动化， 2012， 博士

【摘要】 电网故障的快速准确诊断对加快事故处理和系统恢复进程、保证电力系统的安全运行具有至关重要的作用。多年来,电网故障诊断问题一直是国内外研究的热点,至今尚未得到很好的解决,其主要困难之一就是考虑保护和断路器拒动、误动以及告警信息错误时故障诊断模型的建立与求解。本文研究电力系统故障诊断的解析化建模与求解问题,通过对保护和断路器动作规则进行总结,提炼出通用的故障诊断规则并对其进行解析化表达,构建了一种电网故障诊断的完全解析模型。完全解析模型由反映故障诊断规则的逻辑方程组来表示,方程组的变量包括可疑故障元件的状态、保护和断路器的动作状态以及其拒动、误动情况的逻辑量,方程组的每个解对应着一个逻辑上可行的故障模式。本文系统地研究了完全解析模型的建模和求解方法,以及基于此模型进行电网故障诊断的实用技术。论文的研究成果主要体现在以下几个方面：1、提出了一种用于电网故障诊断的完全解析模型。完全解析模型对诊断规则进行解析化表达,并完整地保留了可疑故障元件、保护动作和断路器跳闸之间固有的逻辑关系,有助于提高电网故障诊断方法的容错能力。2、对完全解析模型的化简和求解方法进行了深入研究。完全解析模型是由隐函数组成的逻辑方程组,求解这种方程组目前还没有通用的方法。本文通过对完全解析模型进行等价变换、关系解耦和自变量与因变量分离,从理论上推导出完全解析模型的化简型,然后结合对告警信号的解析,导出完全解析模型的完备解集。3、提出一种基于完全解析模型的电网故障诊断方法。电网故障诊断过程中存在许多不确定因素,导致完全解析模型解的多重性。通过对这些不确定因素及其分布规律的深入研究,构造了一个反映故障诊断决策风险的综合评价指标,进而把故障诊断问题转化成一个基于风险决策的整数规划问题,然后采用随机优化算法求解并得出故障诊断结论。4、提出一种基于IEC61850的电网故障诊断解析化建模方法。通过解析数字化变电站的系统配置文件,获取电网元件的保护配置信息与保护和断路器之间的关联关系,结合电网的拓扑信息,实现完全解析模型的在线构建。5、提出了一种电网故障告警信息的实时获取方法。通过建立与SCADA系统的数据连接,采用一种动态事件窗生成技术,实现对告警信息序列的有效捕获,结合保护与断路器的关联关系,从捕获的信息序列中提取出电网故障诊断信息。更多还原

【Abstract】 Rapid diagnosis of fault elements plays a crucial role to speed up the process of fault treatment and system recovery when faults occur in a power system, for the secure operation of power systems. Fault diagnosis of power systems has been being an active research area at home and abroad for many years, but the fault diagnosis problem has not yet been resolved completely till now. The main cause is that fault diagnosis of power systems is difficult to be modeled accurately and be solved exactly considering errors of alarms as well as misoperation and failure operation of protective relays and circuit breakers. In this thesis, modeling and solving the fault diagnosis in a complete analytical form are investigated, and a complete analytical model for fault diagnosis is presented. The complete analytical model consists of a set of logical equations representing the diagnostic rules, of which the variables represent the states of faulty elements, actions and malfunctions of protective relays and circuit breakers. Each solution of the model represents a logically possible fault mode interpreting a complete scenario of fault diagnosis. The modeling, as well as simplifying and solving, of the complete analytical model is investigated systematically, and several technologies of fault diagnosis based on the complete analytical model are developed.The main work of this thesis is summarized as follows:1. A complete analytical model for fault diagnosis of power systems is proposed by complete representation of the diagnostic rules. The intrinsic logical relations between the states of faulty elements and actions of protective relays(&circuit breakers) are reserved, contributing to the improvement of the error-tolerance ability of the analytical model.2. Simplifying and solving of the complete analytical model is investigated systematically. The complete analytical model is a set of logical equations consisting of implicit functions, and no effective approaches to solve such logical equations are available by far. With the exploration of the characteristics of the complete analytical model, a simplified version of the model is derived theoretically using equivalent transformations, relation decoupling and separating the independent variables from the dependent ones. The complete solution set of the complete analytical model is obtained by deduction from analysis of the alarms received.3. A fault diagnosis method based on the complete analytical is proposed with various uncertainties in consideration. The complete analytical model has a multiplicity of solutions because of the uncertainties in the process of fault diagnosis. A composite index denoting the decision-making risk of fault diagnosis is built by considering distribution of the uncertainties. The fault diagnosis problem is then transformed into an integer programming problem of risk-based decision making, and the optimal solution of the complete analytical model can be obtained as the result of fault diagnosis by using a stochastic optimization algorithm.4. An approach to construct the complete analytical model is proposed according to the IEC61850standard. The configuration of protection and the logical relationships between the behaviors of protective relays and circuit breakers can be acquired by analyzing the SCD (Substation Configuration Description) file, and the complete analytical model is constructed on line by combining the topology of the power network with the configuration and relationships acquired above.5. An acquisition method of the real-time information for fault diagnosis is proposed by building an online interface to the SCADA system. A sequence of alarms including information for fault diagnosis is intercepted and captured using a technique so-called "generation of dynamic event window" presented by the thesis. From the captured alarms, the fault diagnosis information is then extracted according to the relevance among faulty elements, protection relay actions and circuit breaker trips.更多还原