基于广域信息的振荡中再故障识别与故障元件判断

发布时间：2018-05-18 05:33

本文选题：广域保护 + 综合序分量　；参考：《天津大学》2014年硕士论文

【摘要】：随着互联电网规模和范围的日益扩大,区域电网之间的电气联系日益紧密,加之电力市场开放出现的运行方式多样化以及大量新型控制技术的营运,使得电力系统网络的稳定特性越来越复杂,电网的稳定性问题越来越需要关注。其中,振荡过程中的再故障判别技术作为保障电网安全稳定运行、降低大规模停电风险、提高用户用电可靠性和电能质量的重要手段,有待于进行深入研究。广域测量系统(wide area measurement system,WAMS)的出现和通信技术的发展,为继电保护向新的领域发展带来了动力。本文研究利用广域信息的大电网振荡再故障的识别及故障元件判断识别方法。考虑到振荡中系统的频率偏移对滤序算法的影响,本文采用综合序分量构成差动电流,提出了一种用于识别互联电网振荡后再故障的差动保护原理,该原理利用联络线的单端综合序分量作为启动元件、双端综合序分量构成差动保护,能有效提高经大过渡电阻接地的灵敏度,改善振荡中心附近短路传统负序元件灵敏度低的问题。为进一步识别故障元件,设计了一种智能电子设备(intelligent electronic device,IED)的分类方式和表达方式,并给出了相应的表达式。利用配合关系矩阵描述IED间的相互配合关系,并结合多点方向信息确定与故障元件直接相连的IED,这些IED保护对象的交集即为故障元件。算例分析表明,本文提出的广域保护原理简单易行,不受振荡频率偏移和系统运行方式影响,耐过渡电阻能力强,能很好实现振荡再故障判断及定位,作为现有振荡再故障保护的冗余补充能有效提高保护性能。
[Abstract]:With the increasing expansion of the scale and scope of interconnected power grids, the electrical links between regional power grids are becoming increasingly close, coupled with the diversification of the operation modes of the open electricity market and the operation of a large number of new control technologies. The stability of power system becomes more and more complex, and the stability of power network needs more and more attention. Among them, as an important means to ensure the safe and stable operation of power network, reduce the risk of large-scale power outage, and improve the reliability and power quality of power consumption, the technology of re-fault identification in the oscillation process needs to be deeply studied. The emergence of wide area measurement system (WAMS) and the development of communication technology have brought the impetus to the development of relay protection in new fields. In this paper, a wide area information based method for the identification of large power grid oscillation re-fault and fault element identification is studied. Considering the influence of frequency shift of system on filtering algorithm, a differential protection principle is proposed to identify the oscillation fault of interconnected power network, which is composed of differential current by synthesizing sequence component. In this principle, the single terminal integrated sequence component of the tie line is used as the starting element, and the two-terminal integrated sequence component forms the differential protection, which can effectively improve the sensitivity of grounding through the large transition resistance. The problem of improving the sensitivity of conventional negative sequence elements near the oscillation center is low. In order to further identify the fault elements, a classification and expression method of intelligent electronic device (IEDs) for intelligent electronic devices is designed, and the corresponding expressions are given. The coordination relation between IED is described by using the coordination relation matrix, and the IEDs directly connected with the fault elements are determined with the multi-point direction information. The intersection of these IED protection objects is called the fault element. The analysis of an example shows that the principle of wide area protection proposed in this paper is simple and easy to carry out. It is independent of oscillation frequency offset and system operation mode, and has strong resistance to transition. As a redundant supplement to the existing oscillatory refault protection, the performance of the protection can be improved effectively.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM732

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