电力系统负荷节点在线电压稳定指标研究

Load-Nodal On-Line Voltage Stability Index for Power System

利用同步相量测量单元(phasor measurement unit,PMU)测得任意(非PV)节点及其相邻母线的电压、线路潮流等实时数据,建立一种新的网络等值模型。同时,基于该模型提出了综合考虑负荷节点有功功率和无功功率的在线电压稳定指标;提出在线电压稳定有功功率指标和在线电压稳定无功功率指标分别用作表征负荷节点的有功功率裕度和无功功率裕度,作为对节点(系统)在线电压稳定指标的补充。如果负荷节点在线电压稳定指标值接近临界值1,则表明系统临近电压崩溃。EPRI-36节点仿真分析表明该方法可有效判断系统电压稳定性,适用于在线电压稳定监测和预估。与其他指标的对比结果体现了本文模型和指标的合理性与优越性。最后通过对山东电网500 k V主网负荷节点电压稳定裕度评估简要说明本文所提方法的可行性。

This paper applies phasor measurement unit （PMU） to measure the real-time data including the voltage and power flow of any （non PV） node and adjacent busbar, and constructs a network equivalent model. Meanwhile, we present the on-line voltage stability index with comprehensive consideration of the active power and reactive power of load node based on this model. And we suggest that the on-line voltage stability indexes of active power and reactive power can be used as active power or reactive power margin for the characterization of load node respectively, which can be the supplement to the on-line voltage stability index of node （system）. If the on-line voltage stability index of load note approaches to 1, it shows that the power system draws near voltage collapse. Simulation results of EPRI-36 bus system show that the proposed method can effectively judge the system voltage stability, and is suitable for the monitoring and prediction of on-line voltage stability. Compared with other indexes, the rationality and superiority of the proposed model and index are reflected. Finally, we briefly explain the feasibility of the proposed method through the voltage stability margin evaluation of load node in Shandong 500 kV main network.