结合证据理论和双层规划的电压稳定不确定分析

提出了一种基于证据理论和双层规划的含风电系统静态电压稳定不确定分析方法。首先,以证据理论中基本可信度分配的概念来描述风速不确定性,建立了静态电压稳定不确定分析模型。然后,通过构造多个风电场风速的联合可信度分配,建立风速的若干个超立方体域,从而将原电压稳定不确定分析问题转化为超立方域内最远和最近电压稳定临界点问题。最后,采用双层规划方法分别求解最远和最近临界点问题,得到各超立方域的负荷裕度最大值和最小值,并合成负荷裕度的信任累积概率分布和似然累积概率分布。IEEE 118节点和IEEE 300节点标准系统的计算结果表明,相比传统概率方法,所提模型与方法能够有效描述风速的客观不确定性和主观不确定性信息,利用负荷裕度的信任和似然分布可确定系统发生电压失稳的最小和最大概率,符合电力调度人员的思维习惯。

Uncertainty Analysis of Voltage Stability Based on Evidence Theory and Bilevel Programming

This paper presents a new uncertainty analysis method of static voltage stability for power systems with wind power generators, based on the evidence theory and bilevel programming. Firstly, the uncertainty of wind speed is described by the concept of basic probability assignment(BPA)in the evidence theory, and the uncertainty analysis model of the static voltage stability is developed. Then, a plurality of hypercube domains are obtained by constructing the joint basic probability assignment of the wind speed, and the original uncertainty analysis problem of static voltage stability is transformed into the problem of farthest and closest voltage stability critical point in these hypercube domains. Finally, bilevel programming method is applied to calculate the farthest and closest critical point problem, and the maximum and minimum load margin in these hypercube domains are obtained, then the belief cumulative probability distribution(BCPD)and plausibility cumulative probability distribution(PCPD)of load margin are synthesized. The numerical results of IEEE 118-bus and IEEE 300-bus systems indicate that, compared with traditional probabilistic methods, the proposed model and method can describe the objective and subjective uncertainty information of wind speed, and the minimum and maximum probability of voltage instability can be determined through the BCPD and PCPD of the load margin. It is in line with the thinking habits of power dispatching personnel.