US 12,146,915 B2
Deterioration estimation device and deterioration estimation program for power conversion device
Fujio Kurokawa, Nagasaki (JP); Ritaka Nakamura, Chuo-ku (JP); and Hajime Shiraishi, Chuo-ku (JP)
Assigned to NAGASAKI INSTITUTE OF APPLIED SCIENCE, Nagasaki (JP); and TMEIC Corporation, Chuo-ku (JP)
Appl. No. 17/995,357
Filed by NAGASAKI INSTITUTE OF APPLIED SCIENCE, Nagasaki (JP); and TMEIC Corporation, Chuo-ku (JP)
PCT Filed Mar. 31, 2021, PCT No. PCT/JP2021/013799
§ 371(c)(1), (2) Date Oct. 3, 2022,
PCT Pub. No. WO2021/201090, PCT Pub. Date Oct. 7, 2021.
Claims priority of application No. 2020-067565 (JP), filed on Apr. 3, 2020.
Prior Publication US 2023/0152375 A1, May 18, 2023
Int. Cl. G01R 31/327 (2006.01); H02M 7/5395 (2006.01); H02P 27/08 (2006.01)
CPC G01R 31/327 (2013.01) [H02M 7/5395 (2013.01); H02P 27/08 (2013.01)] 5 Claims
OG exemplary drawing
 
1. A deterioration estimation device for a power conversion device outputting an AC current, the deterioration estimation device comprising:
calculating means for calculating a variation of characteristics of switching elements for power conversion in the power conversion device from a voltage command treated as a target for an output voltage of the power conversion device and an output voltage value of the power conversion device, the calculating means comprising a subtracting means for calculating a difference between the voltage command and the output voltage value;
determining means for determining whether the variation of the characteristics calculated by the calculating means has changed from an initial state by a threshold value or greater, the determining means comprising a first unit for receiving a variation of characteristics signal from a first integrating means, and a second unit for receiving a variation of characteristics signal from a second integrating means; and
notifying means for issuing a warning when the determining means has determined that the change in the variation of the characteristics is equal to or greater than the threshold value, wherein
the calculating means includes polarity determining means for determining a polarity of the AC current outputted from the power conversion device including an upper arm comprising a first switching element among the switching elements and a lower arm comprising a second switching element among the switching elements, and switching means configured to switch the signal from the subtracting means to the first integrating means when the switching signal from the polarity determining means indicates that a positive polarity of the AC current is detected, and switch the signal from the subtracting means to the second integrating means when the switching signal from the polarity determining means indicates that a negative polarity of the AC current is detected, and
the determining means includes a pair of units each of which is respectively configured to determine the variation of the characteristics switched by the switching means.