基于越限风险值指标的电网脆弱环节识别

Identification of vulnerable links in power grid based on out-of-limit risk value index

为了提高电力系统运行的稳定性,针对电网运行时受不确定因素影响会引起线路功率和节点电压越限的问题,考虑风电和负荷波动两个不确定因素提出越限风险值指标识别电网的脆弱环节.首先,分别定义线路功率越限风险值指标和节点电压越限风险值指标;接着,用n-k方法分别模拟电网中的线路断开和节点失效的情况,得到线路越限风险值和节点越限风险值分别对线路和节点进行排序;并利用二元决策图(BDD)算法提高n-k方法的识别效率;然后对IEEE 30节点系统和IEEE 118节点系统进行实验,验证越限风险值指标和n-k识别方法的有效性和普适性;最后分别模拟线路断开和节点故障,基于IEEE 118节点系统的切负荷量来评价识别指标和方法.

In order to improve the stability of power system operation,in view of the problem that the line power and node voltage will exceed the limit due to the influence of uncertain factors during the operation of the power grid,considering the two uncertain factors of wind power and load fluctuation,a risk value index of over-limit risk is proposed to identify the vulnerability of the power grid.link.First,define the risk value index of line power over-limit and node voltage over-limit risk value respectively;then,use the n-k method to simulate the situation of line disconnection and node failure in the power grid respectively,and obtain the line over-limit risk value and node over-limit risk Lines and nodes are sorted by value;and the binary decision diagram(BDD) algorithm is used to improve the identification efficiency of the n-k method;then experiments are carried out on the IEEE 30-node system and the IEEE 118-node system to verify the out-of-limit risk value index and the n-k identification method effectiveness and universality;Finally,the line disconnection and node fault are simulated respectively,and the identification indicators and methods are evaluated based on the load shedding of the IEEE 118-node system.