US 12,081,138 B2
Power conversion device
Takuya Kajiyama, Tokyo (JP); Toshiyuki Fujii, Tokyo (JP); Shuhei Fujiwara, Tokyo (JP); Ryosuke Uda, Tokyo (JP); and Yoshiyuki Kono, Tokyo (JP)
Assigned to Mitsubishi Electric Corporation, Tokyo (JP)
Appl. No. 17/797,272
Filed by Mitsubishi Electric Corporation, Tokyo (JP)
PCT Filed Mar. 11, 2020, PCT No. PCT/JP2020/010630
§ 371(c)(1), (2) Date Aug. 3, 2022,
PCT Pub. No. WO2021/181580, PCT Pub. Date Sep. 16, 2021.
Prior Publication US 2023/0056080 A1, Feb. 23, 2023
Int. Cl. H02M 7/219 (2006.01); H02M 1/08 (2006.01); H02M 1/32 (2007.01)
CPC H02M 7/219 (2013.01) [H02M 1/08 (2013.01); H02M 1/32 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A power conversion device that performs power conversion between a DC circuit and an AC circuit, the power conversion device comprising:
a power conversion circuit unit including a plurality of leg circuits corresponding to a plurality of phases of the AC circuit, each of the leg circuits including a plurality of converter cells each having a capacitor and connected in series to each other, each of the plurality of converter cells being a first converter cell including at least two switching elements or a second converter cell including at least four switching elements; and
a control device to control operations of the plurality of converter cells,
wherein
the control device
operates a plurality of the first converter cells that are controlled not based on a circulating current circulating between the plurality of leg circuits as a voltage source that outputs a circulating voltage in a circulating circuit indicating a closed circuit not including the DC circuit and the AC circuit, and
operates a plurality of the second converter cells to control the circulating current in the circulating circuit.