US 11,735,948 B2
Bi-directional multi-function converter for backup battery unit
Yuan Cao, Sunnyvale, CA (US); Huawei Yang, Sunnyvale, CA (US); and Tianyi Gao, Sunnyvale, CA (US)
Assigned to BAIDU USA LLC, Sunnyvale, CA (US)
Filed by Baidu USA LLC, Sunnyvale, CA (US)
Filed on Jul. 26, 2019, as Appl. No. 16/523,227.
Prior Publication US 2021/0028710 A1, Jan. 28, 2021
Int. Cl. G06F 1/32 (2019.01); H02J 7/34 (2006.01); H02M 3/335 (2006.01); H02J 9/06 (2006.01); H02M 1/08 (2006.01); H02J 7/00 (2006.01); G06F 1/26 (2006.01); H05K 7/20 (2006.01)
CPC H02J 7/34 (2013.01) [G06F 1/26 (2013.01); H02J 7/0013 (2013.01); H02J 9/061 (2013.01); H02M 1/08 (2013.01); H02M 3/33584 (2013.01); H05K 7/20754 (2013.01); H05K 7/20781 (2013.01); H05K 7/20836 (2013.01); H05K 7/20909 (2013.01); H05K 7/20927 (2013.01); H05K 7/20945 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A backup battery unit (BBU) to provide backup power, the BBU comprising:
one or more battery cells arranged in a battery pack; and
a bi-directional direct-current to direct-current (DC/DC) converter coupled to the battery cells, wherein the bi-directional DC/DC converter comprises:
a first terminal coupled to the battery cells;
a coupled inductor having a primary winding coupled to the battery cells and a plurality of secondary windings coupled to a plurality of secondary outputs respectively, wherein the primary winding comprises a first side and a second side;
a switching device comprising a first side and a second side, wherein the first side of the switching device couples directly to the first side of the primary winding, and wherein the second side of the primary winding couples directly to the first terminal;
a second terminal coupled directly to the second side of the switching device, wherein when the second terminal is coupled to an external power supply, the external power supply is configured via the second terminal to charge the battery cells of the battery pack and to provide power to the secondary outputs via the coupled inductor, and wherein when the external power supply is unavailable, the battery cells are discharged to provide power to a primary load external to the BBU via the second terminal and to provide power to the secondary outputs via the coupled inductor; and
a controller configured to control a duty cycle of the switching device, which in turn controls a charging current to charge the battery cells or a discharge current to discharge the battery cells.