US 12,395,067 B2
Protection circuit of resonant converter and operation method thereof
Younghwan Kwack, Seoul (KR); Seongho Son, Seoul (KR); Seonho Jeon, Seoul (KR); Chuhyoung Cho, Seoul (KR); and Jongseong Ji, Seoul (KR)
Assigned to LG Electronics Inc., Seoul (KR)
Appl. No. 17/919,413
Filed by LG Electronics Inc., Seoul (KR)
PCT Filed Apr. 8, 2021, PCT No. PCT/KR2021/004432
§ 371(c)(1), (2) Date Oct. 17, 2022,
PCT Pub. No. WO2021/210848, PCT Pub. Date Oct. 21, 2021.
Claims priority of application No. 10-2020-0046693 (KR), filed on Apr. 17, 2020.
Prior Publication US 2023/0170789 A1, Jun. 1, 2023
Int. Cl. H02M 1/32 (2007.01); H02M 1/00 (2007.01); H02M 3/00 (2006.01)
CPC H02M 1/32 (2013.01) [H02M 1/0058 (2021.05); H02M 3/01 (2021.05)] 14 Claims
OG exemplary drawing
 
1. A protection circuit of a resonant converter including first and second switches, the protection circuit comprising:
a comparator configured to (i) compare a direct current (DC) link voltage of the resonant converter with a voltage across both ends of one of the first or second switches that switches a voltage to a coil and (ii) output one or more signals based on the comparison;
a microcomputer configured to detect whether zero voltage switching is performed and whether the zero voltage switching has failed, based on the one or more output signals from the comparator;
an unstable region removal unit configured to detect, among the one or more output signals, one or more signals indicating that a voltage input to the resonant converter is greater than or equal to a predetermined voltage;
a dead time activation unit configured to detect a signal at a dead time among the one or more signals detected by the unstable region removal unit; and
a signal conversion unit configured to convert the signal detected by the dead time activation unit into a low frequency signal.