电力系统振荡分析及解列策略研究

发布时间：2018-06-14 12:20

本文选题：振荡 + 失步　；参考：《华北电力大学(北京)》2017年硕士论文

【摘要】：解列控制是大规模电网安全保障体系三道防线中的最后一道防线,当电网遭受严重的故障干扰,种种紧急控制措施都无法避免其暂态稳定性被破坏时,解列控制就会按照一定的规则把原系统切割成若干孤岛,以避免故障扩散到整个网络进而引起全系统的崩溃,从而保证大部分负荷仍然可以得到持续的电力供应。随着大规模互联电网的建立,紧急解列控制必然会得到越来越广泛的应用。本文就二机系统和三机系统的失步振荡中心进行定位研究,提出更为完善合理的系统解列策略,取得成果如下:提出考虑线路各点频率差异的二机系统失步振荡中心定位研究方法。假设频率沿线路线性分布,基于此构建更为精确的阻抗模型,推导母线处的测量阻抗,借助阻抗复平面图赋予振荡中心概念数学意义,同时可以更直观、快捷的寻求失步中心,进行失步中心定位和振荡中心漂移分析研究,最后给出失步中心定位判据以及失步中心时刻线路两端发电机功角差与180度比较的分析判据。提出基于多频环状等值三机系统的失步振荡中心定位研究方法。推导节点电压表达式,通过在节点处构建等值虚拟机,将三机系统转换成三个二机系统,并通过比对三个等值系统相角差的特征,构造系统失步振荡中心定位判据,在此基础上,剖析了三机系统在各种不同调工况下振荡中心的漂移规律,仿真结果验证了该方法不仅能精确定位环状多频系统振荡中心,而且能够明确、合理地阐释振荡中心的迁移趋势。提出更为完善合理的解列控制策略。一个完整的解列控制方案,不仅包括电力系统解列断面的确定,也包括辅助的紧急频率控制措施以及电压稳定措施。首先基于慢同调理论进行同调机群识别,其次设计相应的解列控制装置,最后提出基于改进传统切机切负荷策略的辅助稳定控制方案,使之不仅能够满足系统联网运行时在大扰动下维持稳定的要求,也能满足系统解列情形下维持稳定的要求。
[Abstract]:Decoupling control is the last line of defense in the three lines of defense of large-scale power grid security system. When the power network is seriously disturbed by faults, all kinds of emergency control measures cannot avoid the destruction of its transient stability. In order to avoid the spread of the fault to the whole network and cause the whole system to collapse, the decoupling control will cut the original system into several isolated islands according to certain rules, so as to ensure that most of the load can still be supplied with continuous power supply. With the establishment of large scale interconnected power grid, emergency decoupling control will be applied more and more widely. In this paper, the location of the out-of-step oscillation center of the two-machine system and the three-machine system is studied, and a more perfect and reasonable system de-listing strategy is put forward. The results are as follows: a method for locating the out-of-step oscillation center of two-machine system considering the frequency difference of different points is proposed. Assuming the routing distribution along the frequency line, a more accurate impedance model is constructed, and the measurement impedance at the bus line is derived. With the aid of the impedance complex plane diagram, the concept of the oscillation center can be given mathematical significance. At the same time, the out-of-step center can be found more intuitively and quickly. The analysis and research of out-of-step center location and oscillation center drift are carried out. Finally, the criterion of out-of-step center location and the analysis criterion of the power angle difference between the generator at both ends of the line and 180 degrees are given. A method for locating out-of-step oscillation center based on multi-frequency annular equivalent three-machine system is presented. The expression of node voltage is derived. By constructing the equivalent virtual machine at the node, the three-machine system is converted into three two-machine systems, and by comparing the characteristics of the phase angle difference of the three equivalent systems, the criteria for locating the out-of-step oscillation center of the system are constructed. On this basis, the drift law of the oscillation center of the three-machine system under different operating conditions is analyzed. The simulation results show that the proposed method not only can accurately locate the oscillation center of the annular multi-frequency system, but also can clearly locate the oscillation center of the annular multi-frequency system. The migration trend of the oscillation center is explained reasonably. A more perfect and reasonable decoupling control strategy is proposed. A complete de-listing control scheme includes not only the determination of the decoupling section of the power system, but also the auxiliary emergency frequency control measures and voltage stabilization measures. First, the homology group is identified based on the slow homology theory; secondly, the corresponding de-listing control device is designed; finally, an auxiliary stability control scheme based on the improved traditional load cutting strategy is proposed. It can not only meet the requirements of maintaining stability in the case of large disturbances, but also meet the requirement of maintaining stability in the case of system de-listing.
【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】：TM712

【参考文献】