【作者】 周鼎；

【导师】 段献忠； 石东源；

【作者基本信息】 华中科技大学 ， 电力系统及其自动化， 2006， 硕士

【摘要】 长期以来,我国变压器保护正确动作率偏低,误整定是主要原因之一。目前,适用于变压器保护的整定计算软件基本上还是空白,因此其研究具有巨大的理论价值和社会经济效益。本文致力于对该领域内的理论问题和关键技术问题进行研究,包括变压器后备保护整定计算原理、故障计算及方式组合原理与方法、整定计算系统实现及其通用性问题等。本文对变压器接地后备保护与相间后备保护的原理及其整定计算方法进行了研究,分析了零序过流保护中存在零序环流这一特殊情况,对零序环流的方向进行了明确的定义和说明。分析了变压器零序过流保护间的死锁问题,并提出了有效的解锁方法。论文探讨了当前变压器相间后备保护配置存在的问题,并给出了相应的配置优化方法。对电力系统故障计算中变压器的数学模型进行了深入研究,提出在形成节点导纳矩阵时直接将其变比作为复数的处理方法,以取得更为直接和明确的计算结果;采用了运行方式约束条件的方法对元件运行方式变化的相互关联以及变电站内多台变压器中性点切换进行处理,可以在自动计算中有效地结合实际运行特点。在以上工作的基础上,通过对变压器后备保护整定原则以及装置整定项目的归纳分析,构建了基于原则可选和保护装置模版自定义的变压器保护整定计算系统,介绍了系统的总体结构,并对整定原则的自定义及其可扩展性进行了分析与研究。最后,本文通过实例介绍了变压器保护整定计算的流程及实现过程。更多还原

【Abstract】 The correct operation rate of transformer protection is low for a long time in China, miscoordination is one of the main reasons. Now, there is no setting calculation software adapted to transformer protection. Therefore, researching on such software has great academic value and economic benefits. This thesis devote to research on theoretic problems and key technical problems, such as setting principles of transformer backup protection, principles and methods in fault calculation and operation mode combination, realization of setting system and its versatility.This thesis studies the principles and methods of setting calculation of transformer grounding backup protection and phase backup protection, analyses the particular instance that the zero-sequence circle current exists in transformer zero-sequence over-current protection, provides the definitely definition and explain of the direction of the zero-sequence circle current. Then, this thesis researches on deadlock between transformer zero-sequence over-current relays and puts forward the valid methods to break the deadlock. The problems exist in configuration of transformer grounding backup protection is studied, and the method to improve the configuration is put forward.The mathematical model of transformer in fault calculation is researched. In order to gain immediate and definite results, means that taking the ratio as the complex number when the node admittance matrix is forming is adopted. A method of operation mode constraints is proposed aimed to dealing the relevancy of operation mode changes of component and the changes of transformer neutral point, which could effectively combine auto-calculation and the experience of practical operation.In addition, a transformer protection setting calculation system is structured based on optional principles and self-redefinition of the protective relay module by summing up the setting principles of transformer backup protection and setting items of the protection devices. Then, the framework of the system is introduced and self-redefinition of setting principles and its extensibility is discussed. Finally, the thesis illuminates the procedure of transformer protection setting calculation by a example.更多还原