一种电压薄弱负荷节点群的戴维南等值参数跟踪方法研究

Research on a weak voltage node group’s Thevenin equivalents tracing method

提出了用戴维南等值参数对电压薄弱负荷节点群进行监视的一种方案。静态分析中,采用连续潮流法确定负荷节点电压——负荷参数曲线;在负荷变化率相同情况下,根据电压幅值变化量确定电压薄弱负荷节点;考虑低电压水平与电压崩溃的关系,提出电压幅值变化率作为电压薄弱负荷节点分群所观察信息,考虑地理因素,将电压薄弱负荷节点模糊聚类分群;将每个电压薄弱负荷节点群中典型节点电网侧戴维南等值参数跟踪。提出基于潮流的仿真计算方法进行戴维南等值参数跟踪,观测电压薄弱负荷节点群的电压稳定裕度。该方法在IEEE 118节点系统上验证了其有效性。

A method is presented to monitor the weak voltage load node groups with Thevenin equivalents. First, continuation power flow solves voltage-load parameter curves of the load nodes. Then weak voltage nodes are selected with voltage magnitude variation under similar load variation rate. With considering about the relation of low voltage level and voltage collapse, voltage magnitude variation rate is chosen as the observation information of weak voltage load nodes grouping. The weak voltage load nodes are fuzzily clustered according to their similarities and simultaneously the geographic factors are taken into consideration. This paper tracks network side Thevenin equivalents on each typical node of weak voltage load node group and analyzes the problems of Thevenin equivalents computing based on local measurements. Therefore, a power flow data based simulation method to track Thevenin equivalents is proposed, which can observe the voltage stability margin of weak voltage load node group. The simulations on IEEE 118 system show the proposed scheme is effective. This project is supported by National Natural Science Foundation of China （No.50177006）.