US 12,140,613 B2
Open-phase detection circuit and power conversion apparatus
Mohammad Bani Shamseh, Tokyo (JP); and Yoshihiro Tawada, Tokyo (JP)
Assigned to TMEIC CORPORATION, Chuo-ku (JP)
Appl. No. 17/754,459
Filed by TMEIC Corporation, Chuo-ku (JP)
PCT Filed Nov. 5, 2019, PCT No. PCT/JP2019/043328
§ 371(c)(1), (2) Date Apr. 1, 2022,
PCT Pub. No. WO2021/090370, PCT Pub. Date May 14, 2021.
Prior Publication US 2022/0334151 A1, Oct. 20, 2022
Int. Cl. G01R 19/04 (2006.01); H02M 1/00 (2007.01); H02M 7/537 (2006.01)
CPC G01R 19/04 (2013.01) [H02M 1/0009 (2021.05); H02M 7/537 (2013.01)] 6 Claims
OG exemplary drawing
 
1. A power conversion apparatus comprising:
a power conversion circuit configured to convert direct-current power into three-phase alternating-current power; and
a control device configured to generate a two-phase negative-phase current from a three-phase alternating current outputted from the power conversion circuit, and to detect an open phase on an output side of the power conversion circuit based on a magnitude of an amplitude of the two-phase negative-phase current, wherein
the control device includes:
a current conversion unit configured to convert the three-phase alternating current into the two-phase negative-phase current;
an amplitude detection unit configured to calculate the amplitude of the two-phase negative-phase current according to a predetermined function, and to output a first output signal in a case that the amplitude increases to a value more than a predetermined negative-phase current reference value;
a current effective value detection unit configured to output a second output signal in a case that at least one effective value out of a first-phase current effective value, a second-phase current effective value, and a third-phase current effective value of the three-phase alternating current becomes lower than a predetermined current determination value; and
a logic detection unit configured to output an open-phase detection signal based on an AND of the first output signal and the second output signal.