基于谐波闭锁涌流的样本电流分析

分析了二次谐波励磁涌流制动使用的2种差电流：Y,d转换差电流ia-ib和D,y转换差电流ia-i0。分析表明,2种方法识别涌流效果相当,存在转换过程中造成二次谐波减小情况,空投时容易出现误动情况,不宜采用分相闭锁。在基于更真实反映励磁电流的基础上,提出了采用样本电流ia＋xi0判断励磁涌流的方法。理论证明该方法能够有效...

Analysis of Sample Current Based on Harmonic Restraint Inrush Current

By analyzing two-kind differential current(DC) such as: DC with delta-star and with star-delta connection used for second harmonic magnetic inrush current restrained,it shows that the former has no advantage over the later on identifying the inrush,and the decreasing situation of second harmonic is existing in transformation process.In addition,because wrong act may occur when transformer energized,split-phase blocking should not be adopted.A new sample current method for effectively judging the magnetic inrush currents is proposed,it can realize single-phase braking,improve reliability of inrush current blocking and no-load fault sensitivity of magnetic inrush current restraint for transformer differential protection.The new method shows higher sensitivity and reliability than that of other differential current,which is proved by more than 10 000 groups of batch experimental simulation data and field no-load energized examples.