中文摘要：

提出利用过程性能指数评估节点电压凹陷对一般敏感设备的影响程度。首先将电压暂降特性（幅值和持续时间）与CBEMA曲线相结合，得到电压凹陷容忍差值，然后结合年凹陷频次得到电压凹陷容忍差的均值和标准差，最后根据均值和标准差计算出节点电压凹陷过程性能指数，作为评估节点电压凹陷影响程度的指标。以IEEE-30系统为例，将节点电压凹陷过程性能指数与平均严重程度指数的计算结果进行对比，验证了该方法的有效性和实用性。

英文摘要：

The paper estimates the influence extent of node voltage sags on general equipment sensitivity by process performance index. Firstly the tolerant deviation of voltage sag is obtained by combination voltage sag characteristics （ amplitude and duration） with CBEMA curve, and then Combined with the annual frequency mean and standard deviation of tolerant deviation of voltage sag are calculated and process performance index of node voltage sag is obtained according to mean and standard deviation, which is treated as the index to estimate the influence extent of node voltage sags. The paper takes IEEE - 30 as an example, the results of the process performance indices are compared with average severity indices, which proves its effective- ness and practicality.