US 12,143,032 B2
Flying capacitor-type NPC three-level topology
Wei Liu, Hefei (CN); Jiacai Zhuang, Hefei (CN); and Jun Xu, Hefei (CN)
Assigned to Sungrow Power Supply Co., Ltd., Hefei (CN)
Appl. No. 17/636,161
Filed by Sungrow Power Supply Co., Ltd., Hefei (CN)
PCT Filed May 25, 2020, PCT No. PCT/CN2020/092056
§ 371(c)(1), (2) Date Feb. 17, 2022,
PCT Pub. No. WO2021/031642, PCT Pub. Date Feb. 25, 2021.
Claims priority of application No. 201910773027.7 (CN), filed on Aug. 21, 2019.
Prior Publication US 2022/0294362 A1, Sep. 15, 2022
Int. Cl. H02M 7/483 (2007.01); H02M 1/00 (2006.01); H02M 1/32 (2007.01); H02M 7/487 (2007.01)
CPC H02M 7/4837 (2021.05) [H02M 1/0095 (2021.05); H02M 1/32 (2013.01); H02M 7/487 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An NPC three-level topology with a flying capacitor, comprising: two half-bus capacitors and at least one bridge arm, wherein
the at least one bridge arm comprises the flying capacitor, two inner switch units, two outer switch units, and two clamping diodes;
a capacitance value of the flying capacitor is greater than or equal to a preset value, so that a voltage change across the flying capacitor does not cause overvoltage of a switch of the inner switch units and the outer switch units when a short circuit fault occurs;
the two half-bus capacitors are identical; and
the two clamping diodes are identical;
wherein the preset value is a capacitance value of the flying capacitor during a short circuit interval, which ensures that a voltage of a switch in a switch unit is less than a breakdown voltage of said switch.