Granted Patent B2

US 12,562,651 · App. 18/476,814 · Granted Feb 24, 2026

Inventors: Lei Wang (Shenzhen, CN); Wenping Tong (Shenzhen, CN)

Assignee: ECOFLOW INC.

H02M3/33592H02M1/0032H02M1/0058H02M3/01H02M3/33573

Abstract

Claims (46)

1 . A synchronous rectification control method for a resonant converter, the method comprising:

obtaining an output current of the resonant converter;

obtaining a first parameter if the output current is greater than a first current threshold;

obtaining a second parameter if the output current is less than a second current threshold, the first current threshold being greater than the second current threshold, and the first parameter being greater than the second parameter;

establishing a first current hysteresis loop according to the first parameter and establishing a second current hysteresis loop according to the second parameter; and

using the first current hysteresis loop and the second current hysteresis loop to control synchronous rectification of the resonant converter in a load switching working condition,

wherein the first parameter comprises a first lower limit value and a first upper limit value, and the second parameter comprises a second upper limit value and a second lower limit value, the first lower limit value being less than the second current threshold.

2 . The synchronous rectification control method according to claim 1 , wherein using the first current hysteresis loop and the second current hysteresis loop to control the synchronous rectification of the resonant converter in the load switching working condition comprises:

sequentially using the first current hysteresis loop and the second current hysteresis loop to control a secondary-side synchronous rectification power switch of the resonant converter, if the resonant converter is switched from full-load to no-load.

3 . The synchronous rectification control method according to claim 2 , wherein sequentially using the first current hysteresis loop and the second current hysteresis loop to control the secondary-side synchronous rectification power switch of the resonant converter comprises:

controlling the secondary-side synchronous rectification power switch to be turned off if the output current is less than or equal to the first lower limit value;

controlling the secondary-side synchronous rectification power switch to be turned on if a turn-off time of the secondary-side synchronous rectification power switch is greater than a time threshold; and

controlling the secondary-side synchronous rectification power switch to be turned off if the output current is less than or equal to the second lower limit value.

4 . The synchronous rectification control method according to claim 3 , wherein the time threshold is less than or equal to a time corresponding to a difference between the first lower limit value and the second upper limit value.

5 . The synchronous rectification control method according to claim 3 , further comprising:

if the output current is in a region between the first lower limit value and the second upper limit value, first turning off the secondary-side synchronous rectification power switch, then turning on the secondary-side synchronous rectification power switch after a delay of a preset duration, and entering the control of the second current hysteresis loop.

6 . The synchronous rectification control method according to claim 1 , wherein using the first current hysteresis loop and the second current hysteresis loop to control the synchronous rectification of the resonant converter in a load switching working condition further comprises:

sequentially using the second current hysteresis loop and the first current hysteresis loop to control a secondary-side synchronous rectification power switch of the resonant converter, if the resonant converter is switched from no-load to full-load.

7 . The synchronous rectification control method according to claim 6 , further comprising:

when the resonant converter is in a working condition of switching from no-load to full-load, controlling the secondary-side synchronous rectification power switch to be turned on if the output current of the resonant converter is greater than or equal to the second upper limit value; and along with a change of the output current, still controlling the secondary-side synchronous rectification power switch to be turned on if the output current is greater than or equal to the first upper limit value.

8 . The synchronous rectification control method according to claim 1 , further comprising:

using the second current hysteresis loop to control a secondary-side synchronous rectification power switch of the resonant converter, if the resonant converter is in a non-load-switching working condition.

9 . The synchronous rectification control method according to claim 1 , further comprising:

shortening a sampling determination duration of the output current.

10 . A synchronous rectification control method for a resonant converter, the method comprising:

obtaining an output current of the resonant converter;

obtaining a first parameter if the output current is greater than a first current threshold;

obtaining a second parameter if the output current is less than a second current threshold, the first current threshold being greater than the second current threshold, and the first parameter being greater than the second parameter;

establishing a first current hysteresis loop according to the first parameter and establishing a second current hysteresis loop according to the second parameter, wherein the first parameter comprises a first lower limit value and a first upper limit value, and the second parameter comprises a second upper limit value and a second lower limit value, the first lower limit value being less than the second current threshold;

using the first current hysteresis loop and the second current hysteresis loop to control synchronous rectification of the resonant converter in a load switching working condition;

sequentially using the first current hysteresis loop and the second current hysteresis loop to control a secondary-side synchronous rectification power switch of the resonant converter, if the resonant converter is switched from full-load to no-load; controlling the secondary-side synchronous rectification power switch to be turned off if the output current is less than or equal to the first lower limit value; controlling the secondary-side synchronous rectification power switch to be turned on if a turn-off time of the secondary-side synchronous rectification power switch is greater than a time threshold; since there is a delay in switching from the first current hysteresis loop to the second current hysteresis loop, in a region between the first lower limit value and the second upper limit value, first turning off the secondary-side synchronous rectification power switch, then turning on the secondary-side synchronous rectification power switch after a delay of a preset duration, and entering the control of the second current hysteresis loop; and controlling the secondary-side synchronous rectification power switch to be turned off if the output current is less than or equal to the second lower limit value;

sequentially using the second current hysteresis loop and the first current hysteresis loop to control the secondary-side synchronous rectification power switch of the resonant converter, if the resonant converter is switched from no-load to full-load; and

when the resonant converter is in a working condition of switching from no-load to full-load, controlling the secondary-side synchronous rectification power switch to be turned on if the output current is greater than or equal to the second upper limit value; and with a change of the output current, still controlling the secondary-side synchronous rectification power switch to be turned on if the output current is greater than or equal to the first upper limit value.

11 . The synchronous rectification control method according to claim 10 , wherein the time threshold is less than or equal to a time corresponding to a difference between the first lower limit value and the second upper limit value.

12 . The synchronous rectification control method according to claim 10 , further comprising:

using the second current hysteresis loop to control a secondary-side synchronous rectification power switch of the resonant converter, if the resonant converter is in a non-load-switching working condition.

13 . The synchronous rectification control method according to claim 10 , further comprising:

shortening a sampling determination duration of the output current.

14 . A non-transitory computer storage medium, storing a program instruction, the program instruction, when executed by a processor, implementing a synchronous rectification control method for a resonant converter;

the synchronous rectification control method comprising:

obtaining an output current of the resonant converter;

obtaining a first parameter if the output current is greater than a first current threshold;

obtaining a second parameter if the output current is less than a second current threshold, the first current threshold being greater than the second current threshold, and the first parameter being greater than the second parameter;

establishing a first current hysteresis loop according to the first parameter and establishing a second current hysteresis loop according to the second parameter; and

using the first current hysteresis loop and the second current hysteresis loop to control synchronous rectification of the resonant converter in a load switching working condition,

wherein the first parameter comprises a first lower limit value and a first upper limit value, and the second parameter comprises a second upper limit value and a second lower limit value, the first lower limit value being less than the second current threshold.

Assignments (1)

Priority Claims (1)

Continuity (2)

References Cited (16)