具有高容错性能的继电保护自适应比较算法研究毕业论文
2021-09-25 20:10:26
摘 要
我国“西电东送”工程的实施给电力行业的大规模远距离输送电力带来了巨大压力,同时也给现行输电网络的安全有效运行带来了新的严峻挑战。随着广域控制技术的广泛应用,继电保护系统通过广域信息网收集并可利用的信息资源更加丰富,也方便了对电网实现更加快速有效的控制。然而,伴随海量信息的收集利用,出现了更大概率的数据部分缺失或错误,这就对电网继电保护算法的容错性能提出了更高的要求。
本文主要针对基于广域信息网的继电保护自适应算法进行了研究讨论,开展了在数据部分缺失或错误情况下的继电保护高容错性能的算法研究。结合广域信息网的信息融合技术,构建具有高容错性能的关联比较自适应保护算法,同时通过加强关联IED之间关于故障判别结果的协商,使得在数据问题出现不确定性故障进行判别时,利用关联IED的动作信息,进行辅助决策。
首先,介绍了几种常见的继电保护自适应算法,对它们的基本原理进行了详细阐述,并对这几种算法进行了比较分析,介绍了它们各自的工作特点以及优缺点。其中着重介绍了基于方向比较原理的算法,并介绍了在此种情况下可能出现的数据缺失或错误的问题,引出了该种算法情况下的容错性问题,为后文的算法介绍和示例打下了基础。
其次,通过分析研究,选定阐述了基于相关矩阵的电网后备保护算法,对它的原理、结构组成进行了描述,并基于IEEE 5机14节点经典系统作为研究对象,给出了算例进行演示。结果表明,该种算法简单有效,且具有较高的容错性能。
接下来,又阐述了基于免疫算法的后备保护,先对免疫算法的基本原理进行解释,然后对该算法应用于继电保护中的算法原理、结构组成、决策机制等进行了描述,并给出了算例进行说明。结果表明,该种算法在容错性能上有较大的提高。
最后,对本文提及的两种算法进行总结和对比,并提出了融合的可能性,以及对未来继电保护系统的高容错性能研究可能展开的更深层次的工作进行了展望。
关键词:继电保护算法;容错性;信息融合;关联IED
Abstract
The implementation of China's "West-to-East Electricity Transmission " project which includes a large-scaleamp;long-distance transmission of electricity has brought great pressure to the power industry, and brought new challenges to the safe and effective operation of the existing transmission network. With the wide application of wide area control technology, information which are collected from wide area information network can be used more abundant by protective relaying system. And it is also convenient for the power grid to achieve more rapid and effective control. However, with the collection and use of massive information, there is a greater probability of missing or error in the data part, which puts forward a higher request to the fault tolerance performance of the power grid relay protection algorithm.
In this paper, the adaptive algorithm of relay protection based on wide area information network is studied and discussed, and the algorithm of high fault tolerance performance of relay protection is carried out in the case of missing data. Combined with information fusion technology of wide area information network, an adaptive protection algorithm with high fault tolerance performance is constructed. At the same time, make use of the action information of the associated IED to assist decision making by strengthening the negotiation between the IED and the result of fault diagnosis when the data problem is not identified.
Firstly, this paper introduces the several common relay protection adaptive algorithms, their basic principle is discussed in detail, and the comparison and analysis of these algorithms are carried out. The characteristics, advantages and disadvantages of each of them are introduced.The algorithm based on direction comparison is mainly introduced in this paper. In this case, the problem of missing or wrong data is introduced, which leads to the fault tolerance of the algorithm. And lay the foundation of the introduction and the example of the algorithm for the following text.
Secondly, based on the analysis of the research, the paper describes the relevant matrix based backup protection algorithm, its principle and structure are described, and based on the IEEE 5 machine 14 node system as the object of study, a numerical example is given to demonstrate. The results show that the algorithm is simple and effective, and has high fault tolerance performance.
Thirdly, it describes the backup protection based on immune algorithm. First,the basic principle of the immune algorithm is explained, and then the principle, structure and decision mechanism of the algorithm are described. Finally, a numerical example is given. The results show that the proposed algorithm has a great improvement in fault tolerance performance.
Finally, the two algorithms mentioned in this paper are summarized and compared, and the possibility of fusion is proposed. And the research on the high fault tolerance performance of relay protection system in the future is prospected.
Key words: relay protection;fault tolerance;information fusion;correlation;IED
目 录
第1章 绪论 0
1.1课题研究背景 0
1.2继电保护自适应算法 1
1.3国内外研究现状综述 3
1.4本文的主要工作 4
第2章 基于相关矩阵的电网后备保护算法 4
2.1算法系统的结构 4
2.2信息编码 6
2.3基于关联矩阵的算法建立 8
2.4算法示例 10
2.5本章小结 12
第3章 基于免疫算法的后备保护 13
3.1信息编码 13
3.2算法原理 13
3.3决策机构 15
3.4算法示例 15
3.5本章小结 17
第4章 结论及展望 18
4.1结论 18
4.2展望 18
参考文献 19
致 谢 21
第1章 绪论
1.1课题研究背景
出于对我国能源资源和用电负荷的分布问题的考虑,我国制定了“西电东送”的战略规划,其主要目标是要促进西部水力资源与大型煤电资源相结合,既促进了西部地区的相关经济发展,又实现了在全国范围内进行电力资源的配置。进一步的推进全国电网联网,将其建设成“安全、可靠、高效、开放”的电网。而我国“西电东送”工程所带来的大规模、远距离输电压力,给现行输电网络的安全有效运行带来了新的严峻挑战[1]。目前“西电东送”工程中,西南电力东送,采用多条交直流并联线路;西北电力东送采用750kV与330kV高、低压电磁环网运行。全国电力系统在联网初期,交流弱联网等均有可能引起电网的稳定性能减小,保证电力系统安全稳定运行的问题亟待解决。
美国电力行业发展多年,电网运行方面经验丰富,但也发生过“北美8.14”大停电这样严重的电力事故。2003年8月14日16时13分,包括东北部所有地区在内,约有1000万左右用户供电被迫中断。按时间顺序推算,事故始于当日13时31分,Lake Erie岸边的一个电厂因故障退出运行。从15时05分开始到15时45分,连续3条345千伏线路因重力原因下垂严重,不当接触树木,造成对地短路,被保护系统检测到后实行切除。这三条高压线路被切除,使得电流涌向并联运行的低压线路,造成阿克隆附近16条138千伏线路严重过载,于是均被相应的保护系统进行切除,造成阿克隆地区停电。由于此时的电力系统仍可以继续维持运行,当地电力公司(First Energy, FE)的调度员未实施任何举措进行防范处理。当日16时05分,另一条345千伏线路因为负荷过重而发生崩盘,被自动保护装置进行切除操作。至此,长达8分钟的雪崩式系统崩盘正式开始,整个东北部地区的大停电形成,共531台发电机被迫停止运行。此次事故主要是由于电力公司和电网监测中心未能及时做出准确分析判断导致了没有在故障间隙内及时采取有效措施,系统在多重相继开断情况下变得脆弱,以致到最后发展成为波及范围巨大的北美大停电[2,3]。