基于电流相位比较原理的站域保护研究
发布时间：2018-10-05 14:57
【摘要】：随着智能电网技术的不断完善,智能变电站的应用也将越来越广泛,它解决了传统阶梯式后备保护很多问题,比如整定困难,延时长等。在对智能变电站构建方案以及相应保护算法的研究上,国内学者主要针对集中式保护结构进行了大量的探索,利用智能变电站能够实现全站各种信息共享的优势来对变电站站域式保护进行优化。传统电流相差高频保护凭借能抵御系统振荡、在系统非全相运行状态下也能正常工作、构造精简、不需要采集电压等方面的优势,一直作为超高压输电线路的主保护。因此,将电流相位比较原理应用于变电站站域保护当中,利用相差保护的优势来进一步提高站域保护的“四性”是有理论和现实意义的。基于这些原因,本文利用分相电流突变量相位和序电流相位比较原理,对站域保护的实现方案进行深入研究。文章首先简述了智能电网、智能变电站的历史以及发展状况,并对比了各国的进展,发现各国虽然对智能电网研究的侧重不同,但是对于电网性能的描述以及对其追求目标是相同的,即建设安全、环保、高效、经济的新型电网。本文介绍了国内外学者对站域保护的研究现状,包括集中式保护、分布式保护以及站域保护算法;总结了近年来国内对变电站智能化技术的工程应用现状:对于220kV等级以上变电站,不对其进行过程层改造,而对间隔层以上应用IEC61850标准模式;对于低于220kV电压等级的情况,则将IEC61850标准模式应用到过程层及以上。其次,本文在分析传统后备保护的缺陷;介绍现有数字化变电站的结构特点;研究适用于变电站系统的网络结构的基础上,提出了分电压等级独立配置保护的变电站站域保护构建方案,即保留一套传统主保护,配置两套站域主后备保护。同时,采用双星型网络设计了针对不同电压等级的站域保护系统过程层组网方案。本文简述了传统相差高频原理并分析其优缺点,具体研究了应用分相DI、序电流相位比较原理在变电站中线路、母线、变压器的方案和可行性,从而提出了利用电流相位比较原理的站域保护方案。研究了一种新的原理实现方式,即利用捕捉正弦波起始点从而确定断路器采集到的电流相位关系的方法来计算相应电流的相位差。提出了站域保护的跳闸策略并针对变电站特殊问题,如拓扑识别、TA饱和、变压器励磁涌流、断路器失灵,提出了此原理的解决方案。最后,文章利用PSCAD/EMTDC建立变电站拓扑结构并对设计方案进行仿真研究,以Visual Studio为程序开发平台,编写C++和Fortran代码,嵌入PSCAD/EMTDC仿真平台,与构建的电力系统模型一起,构成与实际保护运行特性一致的仿真平台。通过仿真单点故障、断路器失灵、通讯失灵等状况来证明此方案的优势。
[Abstract]:With the continuous improvement of smart grid technology, the application of smart substation will be more and more extensive. It solves many problems of traditional step backup protection, such as difficult setting, long delay and so on. In the research of intelligent substation construction scheme and corresponding protection algorithm, domestic scholars mainly focus on the centralized protection structure for a large number of exploration, Intelligent substation can realize the advantages of all kinds of information sharing to optimize substation protection. The traditional current phase difference high frequency protection is the main protection of EHV transmission line because it can resist the system oscillation, work normally under the condition of the non-phase operation, simplify the structure and do not need the acquisition voltage, etc. Therefore, it is of theoretical and practical significance to apply the principle of current phase comparison to substation field protection, and to further improve the "four properties" of station domain protection by using the advantage of phase difference protection. Based on these reasons, this paper makes a deep research on the realization scheme of the station domain protection by using the principle of phase comparison between the phase of phase current abrupt change and the phase of sequence current. This paper first introduces the history and development of smart grid, smart substation, and compares the progress of other countries. However, the description of power grid performance and the pursuit of its goal are the same, that is, to build a new type of power grid with safety, environmental protection, efficiency and economy. This paper introduces the research status of station domain protection, including centralized protection, distributed protection and station domain protection algorithm. This paper summarizes the engineering application status of intelligent substation technology in China in recent years: for substations above 220kV level, the process layer is not modified, but the standard mode of IEC61850 is applied to the substation above the interval layer, and the voltage level is lower than the 220kV voltage level. Then the IEC61850 standard pattern is applied to the process layer and above. Secondly, on the basis of analyzing the defects of the traditional backup protection, introducing the structural characteristics of the existing digital substation, and studying the network structure suitable for the substation system, In this paper, a scheme of substation station protection is proposed, which consists of one set of traditional main protection and two sets of main backup protection. At the same time, a two-star network is used to design a process layer networking scheme for different voltage levels of the station area protection system. This paper briefly introduces the principle of high frequency phase difference and analyzes its merits and demerits. The scheme and feasibility of applying the principle of phase separation DI, sequence current phase comparison in substation lines, busbars and transformers are studied in detail. Thus, a protection scheme based on the principle of current phase comparison is proposed. In this paper, a new realization method is studied, that is, the phase difference of the corresponding current is calculated by using the method of capturing the starting point of sine wave and determining the phase relation of the current collected by the circuit breaker. The trip strategy of substation protection is put forward and the solution of this principle is put forward aiming at the special problems of substation, such as topology identification of TA saturation, transformer excitation inrush current and circuit breaker failure. Finally, the topology structure of substation is established by PSCAD/EMTDC and the design scheme is simulated. The C and Fortran codes are written on the platform of Visual Studio, and the PSCAD/EMTDC simulation platform is embedded into the simulation platform, which is combined with the power system model. The simulation platform which is consistent with the operation characteristics of the actual protection is constructed. The advantages of this scheme are proved by simulation of single point fault, circuit breaker failure, communication failure and so on.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM63;TM77
[Abstract]:With the continuous improvement of smart grid technology, the application of smart substation will be more and more extensive. It solves many problems of traditional step backup protection, such as difficult setting, long delay and so on. In the research of intelligent substation construction scheme and corresponding protection algorithm, domestic scholars mainly focus on the centralized protection structure for a large number of exploration, Intelligent substation can realize the advantages of all kinds of information sharing to optimize substation protection. The traditional current phase difference high frequency protection is the main protection of EHV transmission line because it can resist the system oscillation, work normally under the condition of the non-phase operation, simplify the structure and do not need the acquisition voltage, etc. Therefore, it is of theoretical and practical significance to apply the principle of current phase comparison to substation field protection, and to further improve the "four properties" of station domain protection by using the advantage of phase difference protection. Based on these reasons, this paper makes a deep research on the realization scheme of the station domain protection by using the principle of phase comparison between the phase of phase current abrupt change and the phase of sequence current. This paper first introduces the history and development of smart grid, smart substation, and compares the progress of other countries. However, the description of power grid performance and the pursuit of its goal are the same, that is, to build a new type of power grid with safety, environmental protection, efficiency and economy. This paper introduces the research status of station domain protection, including centralized protection, distributed protection and station domain protection algorithm. This paper summarizes the engineering application status of intelligent substation technology in China in recent years: for substations above 220kV level, the process layer is not modified, but the standard mode of IEC61850 is applied to the substation above the interval layer, and the voltage level is lower than the 220kV voltage level. Then the IEC61850 standard pattern is applied to the process layer and above. Secondly, on the basis of analyzing the defects of the traditional backup protection, introducing the structural characteristics of the existing digital substation, and studying the network structure suitable for the substation system, In this paper, a scheme of substation station protection is proposed, which consists of one set of traditional main protection and two sets of main backup protection. At the same time, a two-star network is used to design a process layer networking scheme for different voltage levels of the station area protection system. This paper briefly introduces the principle of high frequency phase difference and analyzes its merits and demerits. The scheme and feasibility of applying the principle of phase separation DI, sequence current phase comparison in substation lines, busbars and transformers are studied in detail. Thus, a protection scheme based on the principle of current phase comparison is proposed. In this paper, a new realization method is studied, that is, the phase difference of the corresponding current is calculated by using the method of capturing the starting point of sine wave and determining the phase relation of the current collected by the circuit breaker. The trip strategy of substation protection is put forward and the solution of this principle is put forward aiming at the special problems of substation, such as topology identification of TA saturation, transformer excitation inrush current and circuit breaker failure. Finally, the topology structure of substation is established by PSCAD/EMTDC and the design scheme is simulated. The C and Fortran codes are written on the platform of Visual Studio, and the PSCAD/EMTDC simulation platform is embedded into the simulation platform, which is combined with the power system model. The simulation platform which is consistent with the operation characteristics of the actual protection is constructed. The advantages of this scheme are proved by simulation of single point fault, circuit breaker failure, communication failure and so on.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM63;TM77
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