高压电网继电保护装置可靠性评估

发布时间：2018-06-06 09:11

本文选题：可靠性 + 继电保护　；参考：《华北电力大学》2014年硕士论文

【摘要】：在我国大电网互联的发展战略下,特高压和高压直输电以及特高压交流输电作为远距离、大容量跨区输电的主要方式。各区域电网之间联系的加强,会给人们带来巨大利益,但同时一个小的电网故障,可能引发一场大的连锁故障。继电保护系统作为电力系统的第一道防线,其可靠性的研究至关重要。本文研究了高压电网继电保护装置可靠性评估,其主要工作如下： (1)分析了影响继电保护装置可靠性的多重因素。首先从保护装置自身的维度考虑,分析软件失效、硬件失效以及极少提及的软件-硬件联合失效对可靠性的影响极其失效率的计算模型；其次,从装置外因的维度考虑,介绍人因失效发生的原因以及人因可靠性的失效模型；最后,从检修与维护的维度考虑,分析故障检修、部分检修与全部检修对可靠性的影响效果,为后续基于多重因素的可靠性建模提供了建模依据。 (2)提出了基于三参数Weibulr分布的继电保护装置时变失效率的估算新方法。该方法弥补了传统继电保护装置时变失效率估算方法无法模拟运行初期不存在老化失效的不足。通过迭代法对位置参数进行估计,采用最小二乘法对Weibull分布的形状参数、尺度参数估计。结合某电网实际失效数据,计算了自保护装置投运后的失效率函数,对比分析了传统拟合方法与三参数Weibull分布拟合的拟合效果。 (3)针对线路保护,建立考虑多重因素下的单个继电保护装置和双重化保护的Markov模型。基于恒定失效的假设,将软件-硬件联合失效加入可靠性模型,分析了Markov下影响继电保护装置不可用率的多个参数及不同失效率下最优定检周期的计算方法；基于时变失效因素,首次对部分检修周期与全部检修周期加以区别,结合某电网实际数据,分析了继电保护装置不同检修策略对继电保护不可用率的影响。 (4)提出了基于Markov模型的高压输电线继电保护风险评估方法。通过划分输电线路与保护装置不同状态,针对微机保护装置自检特性,提出了隐性误动风险、显性误动风险、隐性拒动风险和显性拒动风险四个风险；利用Markov模型,推导了四个风险的计算方法；进一步根据某电网直流保护和交流保护的两组实测数据,计算了相应的四个风险,并分析了风险与传统的可靠性指标在评价继电保护可靠性上的差异。
[Abstract]:Under the development strategy of large power grid interconnection in China, UHV and HV direct transmission and UHV AC transmission are the main modes of long-distance and large-capacity transmission across the region. A strong connection between regional power grids will bring great benefits to people, but at the same time, a small power grid failure may lead to a large cascading fault. As the first line of defense of the power system, the research on the reliability of relay protection system is very important. In this paper, the reliability evaluation of relay protection device in high voltage power network is studied. The main work is as follows: 1) the multiple factors affecting the reliability of relay protection device are analyzed. First of all, considering the dimension of the protection device itself, the paper analyzes the calculation model of software failure, hardware failure and the failure rate of software hardware joint failure which is rarely mentioned; secondly, considering from the dimension of device external cause, the model of failure rate of software failure, hardware failure and joint failure of software and hardware is analyzed. This paper introduces the cause of human failure and the failure model of human reliability. Finally, considering the dimension of maintenance and repair, the paper analyzes the effect of fault maintenance, partial maintenance and total maintenance on reliability. It provides the basis for the reliability modeling based on multiple factors. A new method for estimating time-varying failure rate of relay protection device based on three-parameter Weibulr distribution is proposed. This method makes up for the deficiency that the traditional method of estimating the time-varying failure rate of relay protection device can not simulate the aging failure at the early stage of operation. The position parameters are estimated by iterative method, and the shape parameters and scale parameters of Weibull distribution are estimated by least square method. Combined with the actual failure data of a power network, the failure rate function of the self-protection device is calculated, and the fitting effect between the traditional fitting method and the three-parameter Weibull distribution fitting method is compared and analyzed. 3) for line protection, the Markov model of single relay protection device and dual protection is established considering multiple factors. Based on the assumption of constant failure, the software / hardware combined failure model is added to the reliability model, and several parameters affecting the unavailability rate of relay protection device under Markov and the calculation method of optimal check period under different failure rate are analyzed. Based on the time-varying failure factors, the partial maintenance cycle and the whole maintenance period are distinguished for the first time. Combined with the actual data of a power network, the influence of different maintenance strategies of the relay protection device on the unavailability of the relay protection is analyzed. (4) A risk assessment method for high voltage transmission line relay protection based on Markov model is proposed. By dividing the different states of transmission lines and protection devices, according to the self-checking characteristics of microcomputer protection devices, four risks are put forward, namely, recessive misoperation risk, explicit misoperation risk, recessive misoperation risk and overt unmovable risk, and the Markov model is used. The calculation methods of four risks are deduced, and the corresponding four risks are calculated according to two groups of measured data of DC protection and AC protection in a power network. The difference between risk and traditional reliability index in evaluating relay protection reliability is analyzed.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM774

【参考文献】