Research on low-voltage winding current transformer wiring of phase differential protection in 500kV autotransformer
YU Hang1, ZHENG Yu2, JIANG Jiongfeng1, SITU Weiye1, WANG Hao1
1. Zhongshan Power Supply of Guangdong Power Grid Co., Ltd, Zhongshan, Guangdong 528400; 2. Foshan Power Supply of Guangdong Power Grid Co., Ltd, Foshan, Guangdong 528000
Abstract：Phase differential protection uses low-voltage winding current transformer at the low-voltage side in 500kV autotransformer. On the basis of describing the differential protection depolarity wiring for the autotransformer, this paper focuses on analyzing the wiring and polarity of low-voltage winding current transformer in the phase differential protection to solve the difficulties in the current transformer polarity acceptance of the autotransformer differential protection in actual work. Finally, through a load test case of 500kV autotransformer, the actual operating state and action of the protection devices are explained in detail where the polarity of the low-voltage winding current transformer is reversed.
2023, Vol. 24 
