US 11,754,638 B2
Ground fault detection apparatus and method of detecting ground fault
Hung-Chieh Lin, Taoyuan (TW); Jen-Chuan Liao, Taoyuan (TW); Yi-Ping Hsieh, Taoyuan (TW); and Hsin-Chih Chen, Taoyuan (TW)
Assigned to DELTA ELECTRONICS, INC., Taoyuan (TW)
Filed by DELTA ELECTRONICS, INC., Taoyuan (TW)
Filed on Nov. 17, 2021, as Appl. No. 17/528,837.
Claims priority of application No. 110129718 (TW), filed on Aug. 12, 2021.
Prior Publication US 2023/0049346 A1, Feb. 16, 2023
Int. Cl. G01R 31/52 (2020.01); H02J 9/06 (2006.01)
CPC G01R 31/52 (2020.01) [H02J 9/061 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A ground fault detection apparatus configured to detect a ground fault of a three-phase uninterruptible power apparatus, the three-phase uninterruptible power apparatus comprising an AC/DC conversion circuit, and a DC/AC conversion circuit coupled to the AC/DC conversion circuit through a DC bus, the ground fault detection apparatus comprising:
a detection circuit comprising a first detection end and a second detection end, said first detection end being coupled to a first filter circuit between the AC/DC conversion circuit and a first AC side, said first detection end being not only coupled to said first filter circuit, but also commonly coupled to a second filter circuit between the DC/AC conversion circuit and a second AC side, said second detection end being further coupled to an equipment grounding point of the three-phase uninterruptible power apparatus, said equipment grounding point being further coupled to a neutral point of a three-phase power source through a grounding resistor, said three-phase power source being further coupled to the first AC side,
wherein the detection circuit indicates whether the three-phase uninterruptible power apparatus has a ground fault and a location where the ground fault occurs according to a detection voltage between the first detection end and the second detection end.