局部耦合双回输电线路故障分析与保护策略

发布时间：2018-07-03 02:28

本文选题：局部耦合 + 双回输电线路　；参考：《华南理工大学》2014年硕士论文

【摘要】：同塔并架输电方式是我国电网建设的必然趋势，然而我国大多数的双回输电线路为局部耦合的情况，其故障分析与保护整定策略是电网安全稳定运行的重要基础。由于局部耦合双回线路之间存在着复杂的零序耦合，其故障分析方法存在特殊性，而传统保护未考虑局部耦合的影响，保护难以保证动作的正确性。因此，本文主要针对连接三端系统的局部耦合双回输电线路的解耦方法、故障分析方法、零序电流保护特性分析、局部耦合对零序保护的影响和保护整定策略进行深入研究。主要研究内容如下： 1.基于单回输电线路、耦合双回输电线路的解耦理论与方法，构建单回线路、耦合双回线路的电压、电流各模量方程，并通过建立各耦合分界点电压、电流各模量的接口方程，联合不同接地故障情况下的故障边界条件方程，实现一种基于三端电气量的局部耦合双回输电线路故障分析算法。所提方法无需构造复合序网，具有良好的通用性与实用性，为本文对局部耦合线路接地故障对零序保护的影响分析奠定理论基础。基于ATP/EMTP建立的三端局部耦合双回输电线路系统模型进行了全面的仿真验证。 2.为研究局部耦合线路接地故障对零序保护的影响，选取典型的局部耦合双回输电线路，基于三端局部耦合双回输电线路故障分析计算方法，在不同故障位置情况下，针对线路各端的零序保护进行动作特性分析。 3.针对双回线路局部耦合对零序保护的影响进行故障特征分析，基于三端局部耦合双回输电线路故障分析计算方法，建立了局部耦合双回输电线路故障特征表，包含：局部耦合率、两端系统阻抗比、故障过渡电阻等因素下故障位置与故障零序分量的关系。利用该信息库，分析了在不同的局部耦合率与不同系统阻抗比等情况下，双回线路的局部耦合对零序保护的影响，呈现出局部耦合率、系统阻抗比和零序电流超越比三者之间的相互制约关系，为规划、运方和继电保护部门起指导决策作用。 4.基于上述保护动作特性分析，本文提出了局部耦合双回线路各侧零序保护配置新方案，及其整定计算原则。重新分析其保护四性，并对新方案的零序保护进行了灵敏性校验。基于ATP/EMTP构建了三端局部耦合双回输电线路仿真模型；通过全面的仿真分析验证了各侧零序电流保护整定策略的可行性。本文研究工作得到了国家自然科学基金重点项目（51307065），，博士学科点专项科研基金（20100172120033）的资助。
[Abstract]:It is an inevitable trend of power grid construction in our country to share the same tower and parallel transmission line. However, most of the double circuit transmission lines in our country are locally coupled, and their fault analysis and protection setting strategy are the important basis for the safe and stable operation of the power network. Because of the complex zero-sequence coupling between the local coupling double-circuit lines, the fault analysis method has its particularity, but the traditional protection does not consider the influence of local coupling, so it is difficult to ensure the correctness of the operation. Therefore, this paper mainly focuses on the decoupling method, fault analysis method, zero-sequence current protection characteristic analysis, the effect of local coupling on zero-sequence protection and protection tuning strategy. The main contents are as follows: 1. Based on the decoupling theory and method of single circuit transmission line and coupled double circuit transmission line, the equations of voltage and current moduli of single circuit line and coupled double circuit transmission line are constructed, and the interface equations of voltage and current modulus of each coupling boundary point are established. A fault analysis algorithm for local coupled double-circuit transmission lines based on three-terminal electrical quantities is realized by combining the fault boundary condition equations of different grounding faults. The proposed method does not need to construct a composite sequence network and has good generality and practicability, which lays a theoretical foundation for the analysis of the effect of the local coupling line grounding fault on the zero-sequence protection in this paper. The three-terminal local coupling double-circuit transmission line system model based on ATP / EMTP is verified by simulation. 2. In order to study the effect of local coupling line grounding fault on zero-sequence protection, a typical local coupling double circuit transmission line is selected, and based on the fault analysis and calculation method of three-terminal local coupling double circuit transmission line, under different fault locations, The operation characteristics of zero sequence protection at each end of the line are analyzed. 3. According to the fault characteristic analysis of local coupling on zero-sequence protection, based on the fault analysis calculation method of three-terminal local coupling double-circuit transmission line, the fault characteristic table of local coupling double-circuit transmission line is established. The relationship between the fault location and the zero sequence component of the fault is included: the local coupling ratio, the impedance ratio between the two ends of the system, and the fault transition resistance. By using this information base, the effect of local coupling on zero-sequence protection is analyzed under different local coupling rates and impedance ratios of different systems, and the local coupling rate is presented. The relationship between impedance ratio and zero-sequence current transcendence ratio of the system plays a guiding role in decision-making for planning, transportation and relay protection departments. 4. Based on the analysis of the operation characteristics of the protection, a new scheme of zero-sequence protection for each side of the local coupling double-circuit line is proposed, and the principle of setting calculation is also presented in this paper. The four features of the new scheme are analyzed again, and the sensitivity of the zero sequence protection of the new scheme is verified. A three-terminal local coupling double-circuit transmission line simulation model based on ATP / EMTP is constructed, and the feasibility of zero-sequence current protection tuning strategy is verified by comprehensive simulation analysis. The research is supported by the National Natural Science Foundation of China (51307065) and the Ph. D. Research Foundation (20100172120033).
【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】：TM75

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