US 12,424,947 B2
Power supply quality improvement-oriented and fault control-oriented economically-integrated medium-voltage grid-connected device with sic module and adaptive control method therefor
Qi Guo, Changsha (CN); Fan Xiao, Changsha (CN); Xin Wang, Changsha (CN); Fei Jiang, Changsha (CN); Xiaomeng He, Changsha (CN); Liu Long, Changsha (CN); Xinjun Qian, Changsha (CN); and Chunming Tu, Changsha (CN)
Assigned to Hunan University, Changsha (CN)
Filed by Hunan University, Changsha (CN)
Filed on Mar. 24, 2025, as Appl. No. 19/088,122.
Claims priority of application No. 202411384009.7 (CN), filed on Sep. 30, 2024.
Prior Publication US 2025/0226765 A1, Jul. 10, 2025
Int. Cl. H02M 7/487 (2007.01); H02J 3/00 (2006.01); H02M 7/49 (2007.01); H02M 7/5387 (2007.01)
CPC H02M 7/487 (2013.01) [H02J 3/001 (2020.01); H02M 7/49 (2013.01); H02M 7/53875 (2013.01); H02J 2203/10 (2020.01)] 10 Claims
OG exemplary drawing
 
1. An adaptive control method for a fault control-oriented economically-integrated medium-voltage grid-connected device with a silicon carbide (SiC) module, comprising:
obtaining a direct current (DC)-side voltage of a neutral point clamped (NPC) circuit to obtain a first voltage; obtaining a sum of capacitor voltages of cascaded H-bridge (CHB) circuit submodules to obtain a second voltage; and subtracting the first voltage and the second voltage from a third voltage to obtain a first difference, wherein the third voltage comprises a sum of a preset reference value of the DC-side voltage of the NPC circuit and a preset reference value of the sum of the capacitor voltages of the CHB circuit submodules;
performing feedback closed-loop control on the first difference to obtain a reference value of a voltage-stabilizing active current; obtaining a reference value of a reactive compensation current based on a preset reactive compensation instruction; obtaining a sample value of the voltage-stabilizing active current and a sample value of the reactive compensation current of a three-phase bridge arm, and subtracting the sample values from the reference value of the voltage-stabilizing active current and the reference value of the reactive compensation current to obtain a second difference and a third difference, respectively; and performing feedback closed-loop decoupling control on the second difference and the third difference to obtain a three-phase bridge arm modulation wave;
calculating a reference value of an output current of a fourth bridge arm based on distribution network information; obtaining a sample value of the output current of the fourth bridge arm, subtracting the sample value from the reference value of the output current of the fourth bridge arm to obtain a fourth difference; and performing feedback closed-loop control on the fourth difference, and performing feedforward control on an output voltage of the fourth bridge arm additionally to obtain a fourth bridge arm modulation wave;
obtaining a three-phase bridge arm NPC circuit switching signal based on the three-phase bridge arm modulation wave; obtaining a three-phase bridge arm NPC circuit output voltage based on the three-phase bridge arm NPC circuit switching signal; obtaining a fourth bridge arm NPC circuit switching signal based on the fourth bridge arm modulation wave; obtaining a fourth bridge arm NPC circuit output voltage based on the fourth bridge arm NPC circuit switching signal; and performing feedback closed-loop control on a capacitor voltage of each submodule of the CHB circuit separately to obtain a voltage-stabilizing active vector of each submodule of the CHB circuit;
obtaining a three-phase bridge arm CHB circuit switching signal based on the three-phase bridge arm modulation wave, the three-phase bridge arm NPC circuit output voltage, and the voltage-stabilizing active vector of each submodule of the CHB circuit; and obtaining a fourth bridge arm CHB circuit switching signal based on the fourth bridge arm modulation wave, the fourth bridge arm NPC circuit output voltage, and the voltage-stabilizing active vector of each submodule of the CHB circuit; and
performing adaptive control on the fault control-oriented economically-integrated medium-voltage grid-connected device based on the three-phase bridge arm CHB circuit switching signal and the fourth bridge arm CHB circuit switching signal.