US 12,470,120 B2
Non-communication distributed control method and device for cascade system
Hong Liu, Shanghai (CN); Wen Zhang, Shanghai (CN); Wenfei Hu, Shanghai (CN); Cheng Lu, Shanghai (CN); Hongyang Wu, Shanghai (CN); and Baihui Song, Shanghai (CN)
Assigned to Delta Electronics (Shanghai) Co., Ltd., Shanghai (CN)
Filed by Delta Electronics (Shanghai) Co., Ltd., Shanghai (CN)
Filed on Nov. 10, 2022, as Appl. No. 18/054,146.
Claims priority of application No. 202111479103.7 (CN), filed on Dec. 6, 2021.
Prior Publication US 2023/0179079 A1, Jun. 8, 2023
Int. Cl. H02M 1/00 (2007.01); H02M 7/04 (2006.01)
CPC H02M 1/0025 (2021.05) [H02M 1/0009 (2021.05); H02M 7/04 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A distributed control method for a cascade system, the cascade system having at least two power modules cascaded with each other, and each of the power modules having a control module, the method comprising:
S1, taking an output of a closed-loop control for regulating an AC current of the power module as a reference value of a bridge arm voltage;
S2, according to the reference value of the bridge arm voltage, obtaining an amplitude of the bridge arm voltage, taking the obtained amplitude of the bridge arm voltage as a feedback signal, comparing the amplitude of the bridge arm voltage with a set value of the bridge arm voltage, and then superimposed on the active current set value in the form of reverse droop to obtain the active current reference value, and after closed-loop control and regulation together with the AC current of the power module, adjusting the reference value of the bridge arm voltage according to the output of the closed-loop control for regulating the AC current of the power module and the feedback signal; and
S3, controlling the bridge arm voltage according to the adjusted reference value of the bridge arm voltage,
wherein in at least one working mode of the cascade system, a change of parameters reflecting an active current has a monotonic relation with a change of the amplitude of the bridge arm voltage.