10kV零序电流互感器特性及其检测方法研究

发布时间：2018-07-11 14:47

本文选题：零序电流互感器 + 零序保护　；参考：《华南理工大学》2014年硕士论文

【摘要】：随着东莞市城市的发展，东莞电网加速进行城网改造，大部分配网将逐步以电缆线路取代架空线路，电网结构也将由单电源、辐射形供电发展为多电源环形供电，以提高供电可靠性。中性点经小电阻接地方式配置简单、动作迅速，更适应于大中城市以电缆出线为主的配电网络。然而相对于中性点消弧线圈接地方式，10kV配电网采用中性点经小电阻接地方式在我国投入运行时间不长，许多问题尚有待深入研究。据统计，目前东莞电网中曾发生过多起由于二次设备失常引发的问题，其中既包含零序电流互感器选型、安装的问题又包含零序电流互感器检测、维护的问题。零序电流互感器作为系统核心部件之一，对保护、测量装置至关重要，其合理选用和运行将极大提高电网安全性和可靠性。因此，对零序电流互感器进行系统研究，对选型、安装方面存在的问题进行排查，对运行、维护方面的措施进行升级改善，将能有效提高东莞电网的运行效益，，更有助于国内配电网建设与运行的经验积累。本论文首先从理论上分析了电流互感器的工作原理及特性，剖析其误差构成及原因，介绍了电流互感器的型号及其指标含义，并对电流互感器进行分类归纳，列举保护用电流互感器的精度及选型要求。在此基础上，阐述了零序电流互感器有别于一般电流互感器的特殊之处，展示了常用的零序电流互感器型号和种类，分析了零序电流互感器在线路零序保护、变压器零序保护、发电机零序保护、小接地系统故障选线、漏电保护等系统中的应用方式和工作原理。从工程实用的角度，归纳了对零序TA在各主要指标方面的选取原则和要求，对零序TA的安装要求和注意点进行了说明，对零序TA在运行维护进行了介绍。本文重点对东莞供电局一例10kV主变保护越级跳闸案例进行了回顾分析，发现一种导致零序保护拒动的零序TA的典型错误接法，并制定了该类零序TA的改进安装工艺。针对东莞供电局对中低压零序TA升流试验作业中存在的不足，提出一种加装了零序TA升流线的创新性升流试验法，明显提高了作业效率和安全系数。
[Abstract]:With the development of Dongguan city, Dongguan power grid will accelerate the urban network transformation. Most distribution networks will replace overhead lines with cable lines gradually. The power network structure will also be developed from single power supply, radiation power supply to multi-power ring power supply. To improve the reliability of power supply. The neutral point is easy to be configured through the small resistance grounding mode, and it is more suitable for the distribution network with cable outlet in large and medium cities. However, compared with the neutral arc-suppression coil grounding mode, it is not long for 10kV distribution network to use the neutral grounding method with small resistance, and many problems need to be studied deeply. According to statistics, there have been many problems caused by secondary equipment aberrations in Dongguan power grid at present, including the selection of zero-sequence current transformers, the problems of installation and the problems of detection and maintenance of zero-sequence current transformers. As one of the core components of the system, the zero-sequence current transformer is very important to the protection and measurement device. Its reasonable selection and operation will greatly improve the security and reliability of the power network. Therefore, the system research on zero sequence current transformer, the problems in selection and installation, the upgrading and improvement of operation and maintenance measures will effectively improve the operation efficiency of Dongguan power network. More conducive to domestic distribution network construction and operation of the accumulation of experience. In this paper, the working principle and characteristic of current transformer are analyzed theoretically, the error structure and reason are analyzed, the model of current transformer and its index meaning are introduced, and the current transformer is classified and summarized. The accuracy and selection requirements of current transformers for protection are listed. On this basis, the special features of zero-sequence current transformer are expounded, and the types and types of zero-sequence current transformer in common use are shown. The zero-sequence current transformer is analyzed in line zero-sequence protection and transformer zero-sequence protection. The application mode and working principle of generator zero sequence protection, fault line selection of small grounding system, leakage protection and so on. From the point of view of engineering practice, the selection principles and requirements of zero sequence TA in each main index are summarized, the installation requirements and attention points of zero sequence TA are explained, and the operation and maintenance of zero sequence TA are introduced. In this paper, a case of 10kV main transformer protection overstep tripping in Dongguan Power supply Bureau is reviewed and analyzed. It is found that a typical misconnection method of zero-sequence TA, which leads to zero sequence protection rejection, is found, and the improved installation technology of this kind of zero-sequence TA is established. In view of the shortcomings of Dongguan Power supply Bureau in the operation of low and medium voltage zero sequence TA upflow test, an innovative up-current test method with zero sequence TA upflow line is put forward, which obviously improves the working efficiency and safety factor.
【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM452

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