公开(公告)号：US11368017B2

公开(公告)日：2022-06-21

申请号：US16616975

申请日：2018-07-04

Applicant: CHANGSHA UNIVERSITY OF SCIENCE AND TECHNOLOGY

Inventor： Xiangjun Zeng

IPC: H02H9/08 ,  G01R31/52 ,  G01R31/08

Abstract: The present invention discloses a safe operation method for voltage reduction arc suppression of a ground fault phase of a non-effective ground system, for use in ground fault safety operation of a neutral point non-effective ground generator or distribution network. When a single-phase ground fault occurs, an external voltage source is applied at a non-effective ground system side between a bus and the ground, or between a line and the ground, or between a neutral point and the ground, or between a shunting tap of a non-effective ground system side winding of a transformer and the ground, to reduce the fault phase voltage to be lower than the continuous burning voltage of a ground arc, thereby meeting the requirements of long-term non-stop safe operation. The operation means and control method effectively prevent power outages, and improve the reliability and security of power supply.

公开(公告)号：US10892616B2

公开(公告)日：2021-01-12

申请号：US16613409

申请日：2018-07-04

Applicant: CHANGSHA UNIVERSITY OF SCIENCE AND TECHNOLOGY

Inventor： Xiangjun Zeng

IPC: H02H9/08 ,  H02H9/00

Abstract: The proposed invention discloses a safe processing method for active voltage reduction of a ground fault phase of a non-effective ground system, for use in safe processing of a ground fault of a neutral point non-effective ground generator or distribution network. Non-effective ground system side windings of a transformer are equipped with a plurality of shunting taps. When a single-phase ground fault occurs, the shunting tap of the fault phase winding is selected to be short-circuited to ground directly or through an impedance to reduce the fault phase voltage to ensure that the fault point voltage is less than the continuous burning voltage of a ground arc to meet a long-term non-stop safe operation requirements. The proposed method can eliminate the instantaneous single-phase ground fault, suppress the permanent single-phase ground fault current, and limit the rising amplitude of non-fault phase voltage and the risk of non-fault phase insulation breakdown.