US 12,072,392 B2
Short circuit detection device and short circuit detection method
Yuji Takizawa, Tokyo (JP); Haruyuki Kometani, Tokyo (JP); Kenta Motoyoshi, Tokyo (JP); Atsushi Yamamoto, Tokyo (JP); Susumu Maeda, Tokyo (JP); and Nobuaki Muroki, Tokyo (JP)
Assigned to MITSUBISHI ELECTRIC CORPORATION, Tokyo (JP)
Appl. No. 17/438,477
Filed by Mitsubishi Electric Corporation, Tokyo (JP)
PCT Filed Apr. 12, 2019, PCT No. PCT/JP2019/015984
§ 371(c)(1), (2) Date Sep. 13, 2021,
PCT Pub. No. WO2020/208812, PCT Pub. Date Oct. 15, 2020.
Prior Publication US 2022/0146593 A1, May 12, 2022
Int. Cl. G01R 31/52 (2020.01); G01R 31/34 (2020.01); H02K 11/26 (2016.01); H02K 11/27 (2016.01)
CPC G01R 31/52 (2020.01) [G01R 31/343 (2013.01); H02K 11/26 (2016.01); H02K 11/27 (2016.01)] 10 Claims
OG exemplary drawing
 
10. A short-circuit detection method, comprising:
a signal acquisition step of acquiring, from a magnetic flux detector configured to detect a magnetic flux generated in an air gap between a rotor and a stator of a rotating electric machine, a detection signal corresponding to the magnetic flux;
a signal processing step of:
subjecting the detection signal acquired in the signal acquisition step to high-frequency filtering of removing high frequencies which is designed so as to selectively remove a part of odd-order main components which are main components of rotor slot order components being included in the detection signal, and corresponding to orders of space harmonics of slots of the rotor and to remove orders equal to or higher than a predetermined order including the selected at least one component, to thereby selectively separate and pass at least a first-order component and low-frequency even-order components; and
generating a filtered signal being the detection signal subjected to the high-frequency filtering; and
a short-circuit detection step of:
detecting a short circuit of a field winding of the rotating electric machine through use of comparison between a current filtered signal generated in the signal processing step and a past filtered signal which is continuous or non-continuous from the current filtered signal or a delay signal obtained by delaying the current filtered signal by a phase of 180 degrees in an electrical signal, or through use of amplification of at least a part of even-order components included in the filtered signal; and
specifying a short-circuit position in a rotor slot based on the comparison between the current filtered signal and the past filtered signal which is continuous or non-continuous from the current filtered signal or the delay signal obtained by delaying the current filtered signal by the phase of 180 degrees in the electrical signal, or based on the amplification of the at least the part of the even-order components included in the filtered signal.