US 12,136,808 B2
Photovoltaic power generation system and method
Yongbing Gao, Shanghai (CN); Chen Wang, Shanghai (CN); Tiansan Lin, Shanghai (CN); and Yang Hu, Shanghai (CN)
Assigned to HUAWEI DIGITAL POWER TECHNOLOGIES CO., LTD., Shenzhen (CN)
Filed by Huawei Digital Power Technologies Co., Ltd., Shenzhen (CN)
Filed on Mar. 23, 2022, as Appl. No. 17/701,940.
Application 17/701,940 is a continuation of application No. PCT/CN2020/090227, filed on May 14, 2020.
Claims priority of application No. 201910905938.0 (CN), filed on Sep. 24, 2019.
Prior Publication US 2022/0216690 A1, Jul. 7, 2022
Int. Cl. H02H 7/00 (2006.01); H02H 1/00 (2006.01); H02H 7/20 (2006.01); H02J 3/38 (2006.01)
CPC H02H 7/20 (2013.01) [H02H 1/0007 (2013.01); H02J 3/381 (2013.01); H02J 2300/22 (2020.01); H02J 2300/24 (2020.01)] 17 Claims
OG exemplary drawing
 
1. A photovoltaic power generation system, comprising:
an inverter;
a controller; and
at least two direct current branch circuits, wherein each direct current branch circuit comprises a DC-DC converter and a leakage current detection apparatus, an input end of the DC-DC converter is connected to a corresponding photovoltaic unit, and an output end of the DC-DC converter is connected to an input end of the inverter;
wherein the DC-DC converter is configured to perform direct current to direct current conversion on a direct current that is output by the corresponding photovoltaic unit, and then transmit a converted direct current to the inverter;
wherein the inverter is configured to invert the direct current transmitted by the DC-DC converter into an alternating current;
wherein the leakage current detection apparatus is configured to: detect a leakage current of a direct current branch circuit on which the leakage current detection apparatus is located, and send the leakage current to the controller,
wherein the controller is configured to: before the photovoltaic power generation system runs, obtain values and directions of leakage currents of the at least two direct current branch circuits, and detect, based on the values and the directions of leakage currents of each of the at least two direct current branch circuits, a direct current branch circuit in the at least two direct current branch circuits on which an insulation fault occurs, and the controller is further configured to: when the photovoltaic power generation system runs and a value of a leakage current of a particular direct current branch circuit exceeds a preset range, detect that an insulation fault occurs on the particular direct current branch circuit.