US 12,081,167 B2
Method for limiting voltage of module, and apparatus and system for applying the same
Renxian Cao, Anhui (CN); and Zongjun Yang, Anhui (CN)
Assigned to SUNGROW POWER SUPPLY CO., LTD., Anhui (CN)
Appl. No. 16/652,252
Filed by SUNGROW POWER SUPPLY CO., LTD., Anhui (CN)
PCT Filed May 13, 2019, PCT No. PCT/CN2019/086555
§ 371(c)(1), (2) Date Aug. 20, 2020,
PCT Pub. No. WO2020/164199, PCT Pub. Date Aug. 20, 2020.
Claims priority of application No. 201910114213.X (CN), filed on Feb. 14, 2019.
Prior Publication US 2021/0367555 A1, Nov. 25, 2021
Int. Cl. H02S 40/32 (2014.01); H02J 3/12 (2006.01); H02J 13/00 (2006.01)
CPC H02S 40/32 (2014.12) [H02J 3/12 (2013.01); H02J 13/0001 (2020.01)] 18 Claims
OG exemplary drawing
 
1. A method for component voltage limitation, applied in a photovoltaic power generation system comprising an inverter, comprising:
receiving an instruction for enabling voltage limitation or an instruction for suspending voltage limitation, wherein the instruction for enabling voltage limitation is received before the inverter is connected to a grid, and the instruction for suspending voltage limitation is received after the inverter is connected to the grid;
controlling at least one photovoltaic cell in a photovoltaic-cell string to operate in a voltage-limited mode, in response to receiving the instruction for enabling voltage limitation, wherein the photovoltaic-cell string comprises a plurality of photovoltaic cells connected in series, and each of the plurality of photovoltaic cells is a photovoltaic-cell sheet, or a photovoltaic sub-string; and
controlling a photovoltaic cell operating in the voltage-limited mode to resume a normal output, in response to receiving the instruction for suspending voltage limitation;
wherein the voltage-limited mode includes a chopping mode, and in the chopping mode, an output voltage of the at least one photovoltaic cell in the photovoltaic-cell string is controlled based on pulse width modulation (PWM) to ensure that an output of a corresponding photovoltaic cell is controlled with a certain duty ratio.