US 9,812,992 B2
Power conversion system
Kaho Mukunoki, Chiyoda-ku (JP); Toshiyuki Fujii, Chiyoda-ku (JP); Osamu Mori, Chiyoda-ku (JP); Shinzo Tamai, Chuo-ku (JP); Sadao Funahashi, Chuo-ku (JP); Yasuhiko Hosokawa, Chuo-ku (JP); and Kotaro Higashi, Chuo-ku (JP)
Assigned to Mitsubishi Electric Corporation, Chiyoda-ku (JP); and TOSHIBA MITSUBISHI-ELECTRIC INDUSTRIAL SYSTEMS CORPORATION, Chuo-ku (JP)
Appl. No. 15/109,594
Filed by Mitsubishi Electric Corporation, Chiyoda-ku (JP); and Toshiba Mitsubishi-Electric Industrial Systems Corporation, Chuo-ku (JP)
PCT Filed Dec. 3, 2014, PCT No. PCT/JP2014/081951
§ 371(c)(1), (2) Date Jul. 1, 2016,
PCT Pub. No. WO2015/104922, PCT Pub. Date Jul. 16, 2015.
Claims priority of application No. 2014-002069 (JP), filed on Jan. 9, 2014.
Prior Publication US 2016/0329831 A1, Nov. 10, 2016
Int. Cl. H02M 7/48 (2007.01); H02M 7/77 (2006.01); H02M 7/68 (2006.01); H02M 7/483 (2007.01); H02M 1/08 (2006.01); H02M 1/00 (2006.01)
CPC H02M 7/68 (2013.01) [H02M 1/08 (2013.01); H02M 7/48 (2013.01); H02M 7/483 (2013.01); H02M 7/77 (2013.01); H02M 2001/0009 (2013.01); H02M 2001/0025 (2013.01); H02M 2007/4835 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A power conversion system comprising:
a power converter for performing power conversion between plural-phase AC and DC, the power converter including a plurality of legs each having a positive arm and a negative arm connected in series, with a connection point therebetween connected to each phase AC line, the plurality of legs being connected in parallel between positive and negative DC buses; and
a control device for controlling the power converter, wherein
each of the positive arm and the negative arm of each leg is composed of at least one converter cells connected in series and including: a series unit of a plurality of semiconductor switching elements connected in series to each other; and a DC capacitor connected in parallel to the series unit, a terminal of the semiconductor switching element being used as an output terminal,
the control device includes a voltage command generating unit for generating a first voltage command for the positive arm and a second voltage command for the negative arm, to perform output control for each converter cell in the positive arm and the negative arm, and
the voltage command generating unit includes:
a current control unit for calculating control commands for controlling an AC current component flowing through each phase AC line, and a circulating current component for each phase which circulates between the legs; and
a command distributing unit for, on the basis of the control commands and a DC voltage command value for voltage between the DC buses, subtracting voltage drop portions due to inductance values in the positive arm and the negative arm from voltages assigned as outputs of the positive arm and the negative arm, to determine the first voltage command and the second voltage command.