利用电流变化率极值特征的变压器涌流识别研究

发布时间：2018-04-15 04:20

本文选题：电力变压器 + 差动保护　；参考：《电力系统保护与控制》2016年22期

【摘要】：为进一步提高电力变压器差动保护性能,提出一种利用电流变化率极值特征的励磁涌流识别的方法。变压器发生涌流时,三相电流波形至少存在一相以上有间断及尖顶波特性,一个工频周期内电流变化率的极大值与极小值的时间间隔小于半个周期,且不具备周期性特点。而内部故障时,故障电流变化率波形近似呈正弦特征,一个工频周期内极大值与极小值的时间间隔近似为半个周期,且具有周期性特征。利用电流变化率一方面可以削弱非周期直流分量的影响,另一方面可以凸显幅值较小的间断变化临界点的特征,构造了利用电流变化率特征的涌流识别判据及实现方案。最后利用动模试验进行验证,不同情况下的计算分析结果表明该算法原理清晰、判据简单、计算量小,在一个周波内能可靠识别出涌流与内部故障,为进一步提升和优化变压器保护性能提供了有益的理论基础。
[Abstract]:In order to further improve the performance of differential protection of power transformer, a method of inrush current identification based on the characteristics of extreme value of current change rate is proposed.When the inrush current occurs in the transformer, the three-phase current waveform has at least one phase discontinuity and peak wave characteristics, and the time interval between the maximum value and the minimum value of the current change rate in a power frequency period is less than half a period, and there is no periodic characteristic.For internal faults, the waveform of fault current change rate is approximately sinusoidal, and the time interval between maximum and minimum in a power frequency cycle is approximately half a period, and has periodic characteristics.On the one hand, the influence of aperiodic DC component can be weakened by the rate of current change, on the other hand, the characteristic of critical point of discontinuous variation with small amplitude can be highlighted.Finally, the dynamic model test is used to verify the algorithm. The results of calculation and analysis under different conditions show that the algorithm is clear in principle, simple in criterion, small in calculation, and can reliably identify inrush current and internal fault in a Zhou Bo.It provides a useful theoretical basis for further improving and optimizing the performance of transformer protection.
【作者单位】：西安工程大学电子信息学院;西安交通大学电气工程学院;
【基金】：国家自然科学基金资助项目(51207119) 西安工程大学博士启动基金资助项目(BS1018);西安工程大学青年学术骨干支持计划~~
【分类号】：TM41

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