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发明公开
CN109871832A 基于幅值相关度的励磁涌流识别方法及系统 无效 - 驳回

基于幅值相关度的励磁涌流识别方法及系统
摘要：
本发明涉及一种基于幅值相关度的励磁涌流识别方法及系统，该方法包括以下内容：根据变压器联接方式，采样扫描计算变压器三相差流，如果三相差流满足预设条件，则继续采样扫描计算，如果三相差流突变，记录三相差流突变时刻；当发生三相差流突变时，计算设定时间内各采样数据窗对应的三相差流基波与二次谐波的幅值 将设定时间内的三相差流基波与二次谐波的幅值进行曲线拟合；计算设定时间内各采样数据窗对应的三相差流基波与二次谐波的幅值 的相关系数k；判断k在设定时间内是否一直存在k大于预设值，如果是，则表明差流为励磁涌流特性；否则，表明差流为故障电流特性。本发明同时利用了基波与二次谐波幅值及其变化特征，可以很好识别内部故障和励磁涌流。
摘要（英）：

The invention relates to an excitation surge current identification method and system based on amplitude correlation, and the method comprises the following steps: carrying out the sampling scanning calculation of three-phase differential current of a transformer according to the connection mode of the transformer, continuing the sampling scanning calculation if the three-phase differential current satisfies a preset condition, and recording the mutation moment of the three-phase differential current if the three-phase differential current suddenly changes; When three-phase differential current mutation occurs; calculating amplitude values of three-phase differential flow fundamental waves and second harmonic waves corresponding to all sampling data windows in set time according to the three-phase differential flow fundamental waves and the second harmonic waves, wherein the amplitude values of the three-phase differential flow fundamental waves and the second harmonic waves correspondto all the sampling data windows in the set time; setting amplitude of the three-phase differential current fundamental wave and the second harmonic wave within set time to be equal to the amplitudeof the three-phase differential current fundamental wave and the amplitude of the second harmonic wave within the set time.;carrying out curve fitting according to the formula shown in the specification; calculating the correlation coefficient k of the three-phase differential flow fundamental wave and the second harmonic wave corresponding to each sampling data window within the set time; judgingwhether k is always greater than a preset value within a set time or not, and if so, indicating that the differential current is an excitation surge current characteristic; otherwise, indicating thatthe differential current is a fault current characteristic. According to the invention, fundamental wave and second harmonic amplitudes and change characteristics thereof are utilized at the same time, so that internal faults and magnetizing inrush current can be well identified.

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