A novel excitation inductance-based power transformer protection scheme

作者：Jiao Z^*; Ma T; Qu Y; Zhang M; Suonan J

来源：Proceedings of the CSEE, 2014, 34(10): 1658-1666.

DOI：10.13334/j.0258-8013.pcsee.2014.10.018

• Excitation inductance
• Fluctuation
• Inrush current
• Parameter identification
• Time domain
• Transformer

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.

• 出版日期2014