US 12,445,063 B2
Control apparatus, electric power conversion apparatus, and method for detecting failure of AC capacitor
Daiki Terashima, Tokyo (JP); Yoshihiro Tawada, Tokyo (JP); Tomoya Katsukura, Tokyo (JP); and Issei Fukasawa, Tokyo (JP)
Assigned to TMEIC CORPORATION, Chuo-ku (JP)
Appl. No. 18/248,744
Filed by TMEIC Corporation, Chuo-ku (JP)
PCT Filed Sep. 29, 2021, PCT No. PCT/JP2021/035942
§ 371(c)(1), (2) Date Apr. 12, 2023,
PCT Pub. No. WO2023/053289, PCT Pub. Date Apr. 6, 2023.
Prior Publication US 2023/0402939 A1, Dec. 14, 2023
Int. Cl. H02M 7/53 (2006.01); H02M 1/32 (2007.01); H02M 1/36 (2007.01); H02M 7/537 (2006.01)
CPC H02M 7/537 (2013.01) [H02M 1/32 (2013.01); H02M 1/36 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A control apparatus for a power conversion apparatus including at least one AC capacitor disposed on an output side of an inverter and disconnected from a circuit when the AC capacitor malfunctions, the control apparatus comprising:
a current component extractor that acquires current values of a current flowing through the AC capacitor during synchronization control that synchronizes an output voltage from the inverter with a system voltage of a system, the synchronization control performed during activation of the power conversion apparatus with an AC switch on a side facing the system open, and extracts a value of a current component having a frequency synchronized with a frequency of the output voltage from the inverter out of the current values;
a failure evaluator that compares the value of the current component extracted by the current component extractor with a predetermined evaluation value in terms of magnitude, and determines that the AC capacitor malfunctions when the value of the current component is smaller than the predetermined evaluation value; and
a failure information notifier that issues failure information representing that the AC capacitor malfunctions when the failure evaluator determines that the AC capacitor malfunctions during the synchronization control.