发电机组涉网保护及相关问题研究

发布时间：2018-11-03 11:48

【摘要】：随着电力电子装置的大量应用和大容量高压直流输电投入运行,我国电网“电力电子化”和“强直弱交”的特性日益明显。一方面,电网的新特性直接影响发电机组的运行。另一方面,发电机组的容量逐年增大,其运行状况也直接影响电网的安全。在这种新形势下,加强发电机组与电网之间的协调性研究意义重大,而发电机组涉网保护正是影响机网协调的关键因素之一。因此,对发电机组涉网保护进行深入研究十分必要。首先,本文通过对多机系统失磁特点的研究,给出了失磁保护与邻近机组过励限制之间的协调配合原则。其次,本文重点研究了统一潮流控制器(Unified Power Flow Controller,UPFC)对发电机失磁保护的影响,并以此为基础,分别分析了调相机、并联电容器对失磁保护的影响。此外,针对调相机,本文还研究了其接入电网的位置对失磁保护的影响及其对多机系统失磁的影响;针对电容器,本文还研究了电容器的容量对失磁保护的影响。最后,本文研究了电网线路单相重合闸时间延长对发电机组保护的影响,并以华东电网某实际抽水蓄能电厂为例,对发电电动机保护进行了校核。除此之外,本文基于三区域交直流系统等值模型,从理论上分析了受端电网交流线路发生单相永久故障,单相重合闸时间过短导致送端电网失稳解列的机理。
[Abstract]:With the extensive application of power electronic devices and the operation of high-voltage direct current transmission with large capacity, the characteristics of "electric electrification" and "strong direct-to-weak AC" in China's power grid are becoming more and more obvious. On the one hand, the new characteristics of power grid directly affect the operation of generating units. On the other hand, the capacity of generating set increases year by year, and its running condition directly affects the safety of power grid. In this new situation, it is of great significance to strengthen the coordination between generating units and power grids, and the protection of generating units is one of the key factors that affect the coordination of generator networks. Therefore, it is necessary to study the network protection of generator sets. Firstly, the principle of coordination between the lost magnetic protection and the excitations of adjacent units is given through the study of the characteristics of the multi-machine system. Secondly, the effect of unified power flow controller (Unified Power Flow Controller,UPFC) on the protection of generator loss of excitation is studied in this paper. Based on this, the effects of adjustable cameras and shunt capacitors on the protection of loss of excitation are analyzed respectively. In addition, the influence of the location of the camera connected to the power network on the lost magnetic protection and the influence of the capacitance of the capacitor on the loss of magnetic protection are also studied in this paper. Finally, this paper studies the influence of single phase reclosing time extension on generator protection, and takes a practical pumped storage power plant in East China Power Grid as an example to check the generator protection. In addition, based on the equivalent model of three-area AC / DC system, this paper theoretically analyzes the mechanism of the single phase permanent fault of AC transmission line in the receiving end network, and the mechanism that the short reclosing time of the single phase leads to the instability of the terminal network.
【学位授予单位】：华北电力大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM31

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