CAJ | 학술논문

TA饱和是变压器差动保护中待解决的关键问题之一。通过对变压器TA饱和的深入分析及仿真研究，得出结论：TA饱和时，区外故障电流含有大量明显的突变点，而区内故障电流连续。据此结论，文章提出了一种利用小波包变换区分变压器内外部故障的新方法。首先小波包变换分别对TA饱和情况下的内外部故障电流进行分解，然后对分解后的信号进行能量计算，将问题量化，可以直观地观察信号的差异，最后提出判据。仿真验证证明，该方法能够正确区分TA饱和情况下的内外部故障电流，能及时阻止可能造成的损害，并可防止变压器保护误动。
TA포화시변압기차동보호중대해결적관건문제지일。통과대변압기TA포화적심입분석급방진연구，득출결론：TA포화시，구외고장전류함유대량명현적돌변점，이구내고장전류련속。거차결론，문장제출료일충이용소파포변환구분변압기내외부고장적신방법。수선소파포변환분별대TA포화정황하적내외부고장전류진행분해，연후대분해후적신호진행능량계산，장문제양화，가이직관지관찰신호적차이，최후제출판거。방진험증증명，해방법능구정학구분TA포화정황하적내외부고장전류，능급시조지가능조성적손해，병가방지변압기보호오동。
TA saturation is one of the key issues to be solved in transformer differential protection.Deep analysis and simulation study of transformer TA saturation showed that when TA saturates, external fault currents contain a great amount of point mutations, while the internal fault current is continuous.According to the conclusion, we propose a new method for distinguishing transformer internal and external fault based on wavelet packet transform.Firstly, wave-let packet transform respectively decomposes internal and external fault current with TA saturation, then calculates en-ergy of decomposed signals.The difference among signals is quantified and can be observed visually, and finally puts forward the criterion.Simulation results show that the method can distinguish internal and external fault current under the condition of TA saturation and timely prevent possible damage, as well as can avoid transformer differential protec-tion mal-operation.