中文摘要：

针对配电系统电压凹陷评估中存在的不确定性，结合区间运算和现有电压凹陷随机评估方法．提出一种配电系统电压凹陷幅值、频次的区间评估模型与算法。在假设系统参数不变的情况下．重点研究了负荷变化和元件故障率不确定对电压凹陷评估的影响，是现有故障定位法的扩展。针对配电系统的结构特点．在研究区间潮流算法的基础上，提出了基于区间估计的电压凹陷幅值、频次评估的数学模型和评估步骤．对RBTS-母线2配电系统进行的仿真证明，该方法仅需进行1次区间评估，就能求出参数在任意区间段上变化所对应的电压凹陷幅值、频次的变化区间范围。仿真结果与确定参数的评估结果比较．验证了算法的有效性和正确性。

英文摘要：

Aiming at the uncertainties of voltage sag algorithm of voltage sag magnitude and frequency are existing stochastic evaluation methods of voltage sag. influences of load variation and element failure rate evaluation,the interval- based evaluation model proposed,which integrates the interval algorithm On the premise of constant system parameters, on voltage sag evaluation are studied,which is development of existing fault locating method. According to distribution system configuration,the mathematical model and evaluation steps are researched based on the interval power flow algorithm. The simulation for RBTS-2 distribution system proves that,only once of interval evaluation is needed to determine the variation range of sag voltage magnitude and frequency corresponding with the parameter variation in any interval. Comparison of simulative results and results by existing evaluation methods with fixed parameters verifies its effectiveness and correctness.