【作者】 余洪；

【导师】 文明浩； 尹项根；

【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】 现在的电力系统中,电流保护,距离保护,差动保护等保护方法都已经很完善,但是他们都是基于工频相量的,而在特高压长线中,这些方法无法像以前一样完全担当主保护的功能,因此有必要探索基于暂态量的新保护方法。本文分析总结了目前线路保护的特点,发现在超高压长线中,分布电容电流对保护的影响很大,由此提出了两种新型线路保护方法——基于贝瑞隆模型的线路差动保护和能量平衡保护。论文首先介绍了分布电容电流补偿的发展状况,以一段300km长的线路建立仿真模型。最后验证了,采用数字滤波后,把线路简化成Π型模型进行补偿,能改善差动保护动作特性,降低保护动作门槛值,提高其速动性。并且通过分析Π型等值电路掌握了并联电抗器的特性,为下面研究并联电抗器补偿打下基础。论文还以基于贝瑞隆模型的差动保护为例,分析了在用ATP-EMTP仿真软件进行仿真分析时可能出现的误差,通过分析这些误差来源,找到了相应的解决办法,从而为下面的仿真研究打下基础。论文最后详细介绍了能量平衡保护的基本原理,并且通过仿真研究验证了它在超高压线路保护中担任主保护的可行性。接下来以线路分布电容电流补偿为基础,研究并联电抗器对能量平衡保护的影响,通过比较加入并联电抗器和不加时能量平衡保护判据的反映来看,并联电抗器并不会对能量平衡保护造成什么影响。能量平衡保护作为针对超高压输电线路而研究的新型线路差动保护,具有良好的应用前景,现阶段的研究工作也为进一步验证它的可行性打下了基础。更多还原

【Abstract】 In the present power systems, though the protections are already perfect, such as current production, distance production and differential production, they are based on the mains-frequency phasor. In the extra-high-voltage long line, these methods cannot fully play the key role in the protection as before. So it is necessary to explore the new methods based on transient amount.The thesis analyzes the characters of the present circuit production and comes to a conclusion that in the extra-high-voltage long line, the distribution of capacitance and current influences the protection most, then promotes two kinds of new circuit production---The current differential protection based on Bergeron model, and the protection based on the principle of balance of energy.The thesis firstly gives us an introduction of the development of the compensation for the distribution of capacitance and current, and sets up a simulation model by a 300km circuit. Finally it is proved that after using the digital filter, compensating the circuit under the simplifiedΠmodel can improve the performance characteristic of differential production, reduce the performance threshold value, and increase the quick-action. And through the analysis of theΠequivalent circuit, we can get the character of the shunt reactor and lay a foundation for the research of the shunt reactor compensation.The thesis also takes the Bergeron model as an example, analyzes the errors which will appear during the emulation analysis, and find the solutions through the analysis of the sources of the errors, which can make a basic foundation for the following emulation research.The thesis finally introduces the basic theories of energy-balance production in details and proves the feasibility of main protection in the extra-high-voltage long line through the emulation research. Then it takes the compensation of circuit’s distributing capacitance and current as a base, studies the influences of shunt reactor on energy-balance production. It shows that the shunt reactor cannot impact on energy-balance production through the different reflections of criterion of energy-balance production under two different conditions. One is with shunt reactor, the other is not. The energy-balance production against the extra-high-voltage long lines is a new method for circuit differential production. It has good prospects. The present study has laid a foundation for further verification of its feasibility.更多还原