多类型电流互感器混联运行对差动保护的影响研究

发布时间：2018-06-06 17:22

本文选题：多类型电流互感器物理模型 + 混联运行方式　；参考：《中国电力科学研究院》2017年硕士论文

【摘要】：本文在分析不同类型电流互感器暂、稳态特性差异的基础上,研制了电子式电流互感器、TPY级电流互感器及5P级电流互感器的物理模型,在此基础上搭建多类型电流互感器混联运行动模测试平台,研究了多类型电流互感器混联运行特性,从P级电流互感器饱和特性以及不同电流互感器“拖尾”电流特性差异两方面分析了电流互感器混联运行对差动保护的影响,并提出了相应的应对措施。首先,本文从理论上分析了不同类型电流互感器特性之间的差异,调研工程现场不同类型电流互感器混联运行方式,研究多类型电流互感器混联运行动模测试技术,研制与实际电流互感器等效的电磁型电流互感器(包括P级与TPY级)和电子式电流互感器模型,对多类型电流互感器物理模型的关键参数进行测试,分析结果表明物理模型的参数与工程用电流互感器的参数具有较好的一致性。并在此基础上搭建了线路保护用的多类型电流互感器混联运行动模测试系统、变压器保护用的多类型电流互感器混联运行动模测试系统及母线保护用的多类型电流互感器混联运行动模测试系统。其次,以线路保护多类型电流互感器混联运行动模测试系统为例,模拟线路区内、外故障,用MATHCAD软件基于傅氏算法对故障录波进行处理分析,并从谐波和非周期分量两方面研究了电磁型电流互感器在正常传变、轻微饱和及严重饱和三种运行工况下与其他两种电流互感器传变特性的差异,得出P级电流互感器不同饱和程度下,传变二次电流中谐波含量及非周期分量的变化规律。最后,结合动模测试波形分析了基于多类型电流互感器混联运行的差动保护动作特性,在电磁型电流互感器正常传变、轻微饱和及严重饱和三种运行工况下,分析了混联运行情况的差动电流与制动电流曲线,以及差动保护比率特性。研究表明当电流互感器饱和时间小于5ms时,差动保护装置存在误动风险。本文从避免电流互感器发生严重饱和、提升差动保护装置识别严重饱和判据及避免不同电流互感器“拖尾”电流差异对差动保护影响三方面出发,采取相应措施,以减小混联运行引起差动保护误动风险,相关改进措施在动模测试平台上得到了试验验证。
[Abstract]:On the basis of analyzing the difference of transient and steady state characteristics of different types of current transformers, the physical models of TPY current transformers and 5p current transformers of electronic current transformers are developed in this paper. On the basis of this, the test platform of multi-type current transformers is built, and the characteristics of multi-type current transformers are studied. The effect of mixed operation of current transformer on differential protection is analyzed from two aspects: saturation characteristic of P class current transformer and difference of current characteristic of different current transformer. First of all, this paper theoretically analyzes the differences between the characteristics of different types of current transformers, investigates the mixed operation modes of different types of current transformers, and studies the test technology of multi-type current transformers' combined transport operation model. The electromagnetic current transformer (including P class and TPY level) and the electronic current transformer model are developed, which are equivalent to the actual current transformer. The key parameters of the physical model of the multi-type current transformer are tested. The results show that the parameters of the physical model are in good agreement with those of the engineering current transformer. On this basis, a multi-type current transformer combined transport model test system for line protection is built. The multi-type current transformer combined transport model test system for transformer protection and the multi-type current transformer combined transport action model test system for busbar protection. Secondly, taking the line protection multi-type current transformer combined transport model test system as an example, simulates the fault in the line area and outside, uses MATLAB software based on the Fourier algorithm to deal with the fault recording. The difference between electromagnetic current transformer and other two current transformers under normal, slight saturation and severe saturation is studied in terms of harmonic and aperiodic components. The variation law of harmonic content and aperiodic component in secondary current is obtained under different saturation degree of P-level current transformer. Finally, combined with the dynamic mode test waveform, the differential protection operation characteristics based on the mixed operation of multi-type current transformers are analyzed. Under three operating conditions of electromagnetic current transformers, such as normal transmission, slight saturation and severe saturation, the characteristics of differential protection are analyzed. The curve of differential current and braking current and the characteristic of differential protection ratio are analyzed. When the saturation time of the current transformer is less than 5ms, the differential protection device is at risk of misoperation. In this paper, measures are taken to avoid serious saturation of current transformer, to identify serious saturation criterion of differential protection device and to avoid the effect of "trailing" current difference of different current transformer on differential protection. In order to reduce the misoperation risk of differential protection caused by mixed operation, the related improvement measures are verified by test on the dynamic model test platform.
【学位授予单位】：中国电力科学研究院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM452;TM773

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