Abstract：This paper analyzes the series of impacts on the transformer protection caused by the sharp rise of the full load current of the power grid with high current carrying capacity. Taking the actual project as an example, it points out that the selection of high transformation ratio current transformers for side and middle switches will affect the protection sensitivity judged by the fixed threshold and the reliability of the differential protection based on the fault component principle. At the same time, the protection setting may exceed the upper and lower limits of the setting value. After the current carrying capacity of the line is greatly increased, the through load current at the high-voltage side of the main transformer is far greater than the rated current of the transformer, which may cause the reliability and sensitivity of the conventional differential protection to decline. Combined with the project imple- mentation, this paper suggests that the main protection and backup protection should be configured with bushing transformer as the protection redundancy scheme to reduce the impact of high current carrying capacity and high transformation ratio.
顾乔根, 张晓宇, 朱, 佳, 谢, 华, 莫品豪. 高载流容量电网的主变保护适应性分析[J]. 电气技术, 2023, 24(1): 96-100.
GU Qiaogen, ZHANG Xiaoyu, ZHU Jia, XIE Hua, MO Pinhao. Adaptability analysis of transformer protection in power system with high current carrying capacity. Electrical Engineering, 2023, 24(1): 96-100.
2023, Vol. 24 
