US 12,407,243 B2
Leakage current suppression method for string photovoltaic system
Yiming Wang, Ningbo (CN); Wenping Zhang, Ningbo (CN); Po Xu, Ningbo (CN); and Wanshuang Lin, Ningbo (CN)
Assigned to GINLONG TECHNOLOGIES CO., LTD., Ningbo (CN)
Appl. No. 18/691,110
Filed by GINLONG TECHNOLOGIES CO., LTD., Ningbo (CN)
PCT Filed Aug. 24, 2023, PCT No. PCT/CN2023/114697
§ 371(c)(1), (2) Date Mar. 12, 2024,
PCT Pub. No. WO2024/066831, PCT Pub. Date Apr. 4, 2024.
Claims priority of application No. 202211175562.0 (CN), filed on Sep. 26, 2022.
Prior Publication US 2025/0219526 A1, Jul. 3, 2025
Int. Cl. H02M 1/088 (2006.01); H02J 3/38 (2006.01); H02J 3/44 (2006.01); H02M 1/00 (2006.01); H02M 7/493 (2007.01)
CPC H02M 1/088 (2013.01) [H02J 3/381 (2013.01); H02J 3/44 (2013.01); H02M 1/0038 (2021.05); H02M 7/493 (2013.01); H02J 2300/24 (2020.01)] 12 Claims
OG exemplary drawing
 
1. A leakage current suppression method for a string photovoltaic system, comprising the following steps:
S100, inputting synchronous carriers to a plurality of parallel inverters included in the photovoltaic system;
S200, carrying out carrier modulation on the inverters;
S300, controlling the switching states of the inverters according to the result of carrier modulation, and then dislocating common-mode components output by the inverters, so that part of the common-mode components of the inverters are canceled out, and the potential variation of the common-mode components output by the photovoltaic system is reduced;
in step S200, the carrier modulation is space vector modulation, and the specific modulation process comprises the following steps:
S210, numbering the inverters #1, . . . , #n in sequence;
S220, carrying out space vectorization on the output voltage of the inverter to obtain a synthesized vector of the output voltage of any inverter and corresponding vector action time;
S230, allocating a starting small vector of the inverter #1, and taking a corresponding redundant small vector as a starting small vector of the next inverter until the redundant small vector corresponding to the inverter #n-1 is the starting small vector of the inverter #n; and
S240, respectively forming the switching state action sequence of each inverter according to the allocated starting small vector.