【作者】 王明宣；

【导师】 黄少锋；

【作者基本信息】 华北电力大学（北京） ， 电力系统及其自动化， 2010， 硕士

【摘要】 本论文的主要工作是研究超高压输电线路采用距离保护与光纤差动保护时所面临的一些特殊问题。主要进行了以下工作：首先,对接地故障情况下弱馈侧的电流、电压以及测量阻抗的情况进行了详细的分析。并提出了引入电流、电压按相补偿的接线方式,解决了弱馈侧非故障相误动的问题。理论分析和仿真结果验证了新方法的有效性。其次,提出了一种防止光纤差动保护非同步采样误动的措施。这种措施最大程度的减小了非同步采样情况下,差动保护误动的几率。仿真结果验证了新措施的有效性。最后,对CT饱和的过程、特征进行了介绍,并详细分析了CT饱和对二次电流的影响,为工程实践中判定CT饱和状态提供了理论依据。更多还原

【Abstract】 The thesis is focus on the research of distance protection and current differential protection in EHV&UHV transmission line. The significant achievements are as follows:Firstly, in cognizance of grounding fault at the weak-infeed side, carried out a detailed analysis of the current, voltage and measured impedance. And present a new residual current and voltage compensation method based on the current and voltage magnitude of each phase for Mho elements. It has been shown that the above compensation manner may have positive impact on the distance protection.Secondly, a new measure to prevent current differential protection maloperation is presented in the paper. This measure is based on phase difference, in connection with the maloperation which is caused by asynchronous sampling. It has been shown that the measure is an effective method.Finally, the characteristics of CT saturation and the impact of CT saturation on the secondary current have been analyzed. And provide a theoretical basis to the engineering practice about how to determine CT saturation state.更多还原