中文摘要：

为进一步提高电力变压器保护的性能，提出一种基于励磁电感参数识别的变压器快速主保护方案。通过分析T型等效电路中励磁电感在变压器正常运行、铁芯饱和以及内部故障时的特点，构建了基于励磁电感数值大小和波动性的变压器保护判据。研究表明：时域参数识别方法计算得到的励磁电感，在正常运行和外部故障时其数值较大；在内部故障时，由于故障电流为差动电流的一部分，励磁电感的计算数值较小；在铁芯饱和时数值在较大值和较小值之间波动。由于保护判据中考虑了铁芯饱和对励磁电感数值的影响，因此该保护方案能够快速灵敏地识别变压器故障，且不受励磁涌流的影响，具有良好的性能。动模试验验证了该保护方案的有效性，试验结果表明，该方案能够可靠地识别变变压器内部故障。

英文摘要：

To improve the performance of power transformer protections, a novel excitation inductance-based transformer protection scheme was studied. By analyzing the characteristics of excitation inductance in T-type equivalent circuit under the condition of normal operation, iron-core saturation and internal fault, the magnitude and the fluctuation of excitation inductance were used to distinguish internal faults from external faults and iron-core saturation conditions. Under normal operation or external fault conditions, the magnitude of excitation inductance is large. When an internal fault occurs, the magnitude of calculated excitation inductance is small because the fault current is included in the differential current. The fluctuation of excitation inductance can be detected if iron-core saturation occurs. The proposed excitation inductance-based protection scheme can detect faults of power transformers sensitively and rapidly with considering iron-core saturation in constructing the criteria. The proposed power transformer protection scheme was verified by many dynamic tests in our laboratory. The test results show that the proposed protection scheme can reliably detect and isolate the fault.