US 11,728,639 B2
Transformer short-circuit protection method and transformer short-circuit protection device
Zehua Zhou, Shanghai (CN); Shengzou Yue, Shanghai (CN); Hongyang Wu, Shanghai (CN); Liping Sun, Shanghai (CN); and Qianfeng Li, Shanghai (CN)
Assigned to DELTA ELECTRONICS (SHANGHAI) CO., LTD., Shanghai (CN)
Filed by Delta Electronics (Shanghai) Co., Ltd., Shanghai (CN)
Filed on Nov. 4, 2021, as Appl. No. 17/453,491.
Claims priority of application No. 202011260069.X (CN), filed on Nov. 12, 2020.
Prior Publication US 2022/0149612 A1, May 12, 2022
Int. Cl. H02H 7/04 (2006.01); G01R 31/62 (2020.01)
CPC H02H 7/04 (2013.01) [G01R 31/62 (2020.01)] 16 Claims
OG exemplary drawing
 
1. A transformer short-circuit protection method, comprises:
acquiring output voltages of a plurality of output lines of at least one winding on a low-voltage side of a transformer;
computing a plurality of line voltages between each two of the plurality of output lines according to the output voltages; and
determining a short circuit when variations of the plurality of line voltages satisfy short-circuit variation characteristics, and sending a protection signal when the short circuit is determined,
wherein the short-circuit variation characteristics comprise an amplitude characteristic in which an amplitude of one of the plurality of line voltages is less than or equal to a first characteristic value within a detection window time, an amplitude of any one of other line voltages is greater than or equal to a second characteristic value within the detection window time, and the first characteristic value is less than the second characteristic value.