Transformer Differential Protection Criterion Based on Reconstructed Trajectory of Current Characteristics in Two-dimensional Space [二维空间重构电流特征轨迹的变压器差动保护判据]

作者：Weng H.; Jia Y.^*; Li Z.; Huang J.; Lin X.; Liu L.

来源：Automation of Electric Power Systems, 2020, 44(9): 144-150.

DOI：10.7500/AEPS20190612003

• Current characteristic trajectory
• Phase angle feature
• Reconstruction in two-dimensional space
• Saturation of current transformer
• Transformer differential protection

With the influence of the fault current, the current transformers (TAs) on both sides of the transformer differential protection are prone to saturation, which would distort the current waveforms of the transformer and seriously affect the correct operation of the transformer differential protection. To solve the problem of misoperation or operation failure of transformer differential protection caused by TA saturation, the phase relationship characteristics between the currents on both sides of the transformer with different fault types are comparatively analyzed. A novel criterion for transformer differential protection is proposed to identify various faults accompanied by the TA saturation, which is based on the two-dimensional reconstruction of currents on both sides and the reconstructed characteristic trajectories. The results of simulation and experimental tests indicate that the proposed criterion has high reliability and sensitivity, as well as the high anti-saturation ability of TA.

• 单位
  三峡大学; 华中科技大学; 强电磁工程与新技术国家重点实验室