利用模糊识别法改进变压器差动保护二次谐波原理

本文分析了变压器差动保护中传统方案二次谐波原理存在的缺陷,在此基础上,引入模糊识别法对其进行改进。充分挖掘判据的自适应性,不再使用单一划线式的“一刀切“门槛阈值,更好地匹配三相差流间的关系,相互制衡,在综合隶属度判据中采用反时限特征,使改进后的模糊识别二次谐波判据效果更加理想。此判据原理简单,科学合理,易于实现,在动作速度和防误动方面都有很大的进步。

Improve the theory of 2nd harmonic used in transformer differential protection by introducing fuzzy recognition

This paper analyzes the defects of the theory of 2nd harmonic which is traditionally used in transformer differential protection,and based on it,the fuzzy recognition is introduced to improve it.The improved fuzzy recognition criterion of 2nd harmonic has even better results by making use of the adaptive criterion,canceling a single line of the "across the board" threshold,better matching the relationship between three differential current,and taking advantage of the feature of inverse time used in the integrated Degree of Membership.This criterion is simple,scientific and reasonable in principle,and easy to implement.It has great progress both in the operational speed and anti-misoperation.