US 11,870,238 B2
Protection apparatus and protection method for photovoltaic power generation system
Xiufeng Zhang, Dongguan (CN); and Yanzhong Zhang, Shanghai (CN)
Assigned to Huawei Digital Power Technologies Co., Ltd., Shenzhen (CN)
Filed by Huawei Digital Power Technologies Co., Ltd., Shenzhen (CN)
Filed on Nov. 24, 2021, as Appl. No. 17/535,375.
Application 17/535,375 is a continuation of application No. PCT/CN2021/081165, filed on Mar. 16, 2021.
Claims priority of application No. PCT/CN2020/084500 (WO), filed on Apr. 13, 2020.
Prior Publication US 2022/0085596 A1, Mar. 17, 2022
Int. Cl. H02H 3/087 (2006.01); H02S 40/32 (2014.01); H02S 40/36 (2014.01); H02H 3/18 (2006.01)
CPC H02H 3/087 (2013.01) [H02H 3/18 (2013.01); H02S 40/32 (2014.12); H02S 40/36 (2014.12)] 33 Claims
OG exemplary drawing
 
1. A photovoltaic power generation system, wherein the photovoltaic power generation system comprises:
a protection apparatus;
a power circuit; and
a plurality of photovoltaic units;
wherein the protection apparatus comprises a direct current bus, a controller, a plurality of protection switches, and a plurality of interfaces;
wherein the protection apparatus is connected to the plurality of photovoltaic units via the plurality of interfaces, the plurality of photovoltaic units are coupled to the direct current bus inside the protection apparatus to form at least one branch, and each branch of the at least one branch is connected to at least two photovoltaic units connected in parallel;
wherein the power circuit is a direct current-direct current (DC-DC) conversion circuit or a direct current-alternating current (DC-AC) conversion circuit, and the power circuit is connected to the direct current bus; and
wherein the controller is configured to:
detect, based on a parameter detection value of the at least one branch or a parameter detection value of the direct current bus, that the photovoltaic power generation system is faulty; and
based on having detected that the photovoltaic power generation system is faulty, control the plurality of protection switches to disconnect at least some of the plurality of photovoltaic units from the direct current bus, to reduce a quantity of photovoltaic units connected in parallel, so that a maximum of three of the plurality of photovoltaic units are connected in parallel.