CAJ | 학술논문

变压器差动保护中传统的二次谐波制动方案在变压器空载合闸、内部故障或外部故障切除时，若TA饱和，变压器差流中二次谐波含量较低，差动保护容易误动。文章对变压器差流进行了谐波分析，针对传统二次谐波制动存在的一些问题，提出了基于二次谐波幅值和相位综合判据的二次谐波制动法。研究了励磁涌流中二次谐波与基波之间特殊的相位关系，通过与二次谐波含量构成自适应调整二次谐波制动系数的综合制动判据，并用EMTP进行大量仿真实验，验证了所提出方案正确性和可靠性。
변압기차동보호중전통적이차해파제동방안재변압기공재합갑、내부고장혹외부고장절제시，약TA포화，변압기차류중이차해파함량교저，차동보호용역오동。문장대변압기차류진행료해파분석，침대전통이차해파제동존재적일사문제，제출료기우이차해파폭치화상위종합판거적이차해파제동법。연구료려자용류중이차해파여기파지간특수적상위관계，통과여이차해파함량구성자괄응조정이차해파제동계수적종합제동판거，병용EMTP진행대량방진실험，험증료소제출방안정학성화가고성。
If the TA is saturated, low second harmonics in transformer differential current will cause false action for differential protection, when the traditional second harmonic restraint strategy is adopted for transformer differential protection in transformer load switching, internal or external fault removal.The harmonic analysis is carried out for the differential current in this paper.Aiming at the problems in traditional second harmonic restraint, a new second har-monic restraint strategy is proposed based on the amplitude and phase of the second harmonic comprehensive criterion. The phase relationship between the fundamental and the second harmonic in inrush current has been researched.The integrated brake criterion is constituted by the second harmonic restraint coefficient adaptively with the second harmon-ics.EMTP simulation results verify the correctness and reliability of the proposed scheme.