中文摘要：

现有的电能质量预警方法通常是依据各类国家电能质量标准的限值设置预警阈值从而判断是否需告警,而此类预警阈值的设置在许多应用场合会显得比较僵硬.针对此缺点,提出了一种有效利用模糊聚类的电能质量预警方法来改善预警阈值的灵活性与适用性.首先对预警对象的电能质量指标值进行模糊聚类分析,得到其动态聚类图,并将各指标水平相近的预警对象划分为同一类型;然后考虑到同类型预警对象的指标值比较接近,选取指标值的算术平均值设为阈值,使阈值的设置更具灵活性,能充分反映真实数据所隐藏的规律;最后在判断是否“超国标”的基础上,根据所设的阈值挖掘电能质量指标在“超标”和“不超标”两种情况下的变化规律,并作告警判断,做到因情而异.通过实例分析,验证了该方法的有效性和实用性.

英文摘要：

The existing early-warning methods of power quality to set warning thresholds are usually based on a variety of limits of national quality standards in order to determine whether need the alarm,but such warning threshold setting in many applications will become much rigid.To deal with this shortcoming,a new method of applying fuzzy clustering to study the power quality early-warning method is proposed to improve the flexibility and applicability of warning threshold.Firstly,the power quality index value of the objects being early warned was analyzed with the theory of fuzzy clustering,the dynamic clustering figures were obtained,and the warning objects with the similar levels of each index were classified into the same category.Since then the value of the same type of early warning objects＇ indexes relatively close,the arithmetic mean value of the same type of warning indexes was set as the early warning threshold so that the threshold setting would be more flexible and scientific,and could adequately reflect the hidden rule of the true data.Finally,on the basis of judging whether ＂super-national standard＂,mining variation of power quality according to the set threshold under the situations of ＂exceed the threshold＂ and ＂do not exceed the threshold＂,and made judgments,and did varies because of the situation.Example analysis result verifies the effectiveness and practicality of the method proposed in this paper.