一种电压暂降对敏感设备影响程度评估的新方法

New Method for Estimating Influence Degree of Sensitive Equipment to Voltage Sag

提出利用电压暂降强度指标评估电压暂降对敏感设备的影响程度。首先定义电压暂降容忍差的概念,确定实际电压暂降幅值与其对应持续时间的电压暂降容忍限值的偏差,反映单一事件对敏感设备的影响程度,然后结合年暂降频次计算出电压暂降容忍差的均值和标准差,最后根据均值和标准差计算出电压暂降强度指标、总电压暂降强度指标,作为评估电压暂降对敏感设备影响程度的指标。该方法考虑各电压暂降容忍差值的大小以及分布情况,有效避免了单一事件影响程度过大带来的误判。通过实例计算,将电压暂降强度指标、总电压暂降强度指标与系统平均有效值波动频率指标(SARFI-Curve)、能量指标进行对比,验证了该方法的有效性和实用性。

The method of sag strength index is proposed to estimate the influence degree of voltage sags on sensitive equipment. The conception of tolerant deviation of voltage sag is defined, which determines the deviation between practical amplitude and tolerant limit of voltage sag with the same duration, and reflects the influence degree of single event on sensitive equipment. Combined with the annual frequency, the mean and standard deviations of tolerant deviation of voltage sag are calculated, and the sag strength index and the total sag strength index are obtained according to the mean and standard deviations, which are treated as the indexes to estimate the influence degree of voltage sags. The method considers the value and the distribution of tolerant deviation of voltage sag, and avoids the disadvantage of the big influence degree of single event availably. Through case calculation, the sag strength index and the total sag strength index are compared with System Average RMS variation Frequency Index （SARFI-Curve） and voltage sag energy indices, thus the effectiveness and practicality of the proposed method are validated.