US 11,916,501 B2
Driving device, compressor, and air conditioner
Masahiro Nigo, Tokyo (JP)
Assigned to Mitsubishi Electric Corporation, Tokyo (JP)
Appl. No. 17/272,755
Filed by Mitsubishi Electric Corporation, Tokyo (JP)
PCT Filed Nov. 21, 2018, PCT No. PCT/JP2018/042930
§ 371(c)(1), (2) Date Mar. 2, 2021,
PCT Pub. No. WO2020/105131, PCT Pub. Date May 28, 2020.
Prior Publication US 2021/0211085 A1, Jul. 8, 2021
Int. Cl. H02P 27/08 (2006.01); H02P 29/60 (2016.01); F25B 31/02 (2006.01); G01R 19/165 (2006.01); G01R 19/32 (2006.01); H01F 1/053 (2006.01); H02K 1/02 (2006.01); H02K 1/276 (2022.01); H02P 25/18 (2006.01); H02P 29/024 (2016.01)
CPC H02P 27/08 (2013.01) [F25B 31/026 (2013.01); G01R 19/16571 (2013.01); G01R 19/32 (2013.01); H01F 1/053 (2013.01); H02K 1/02 (2013.01); H02K 1/276 (2013.01); H02P 25/184 (2013.01); H02P 29/027 (2013.01); H02P 29/60 (2016.02)] 15 Claims
OG exemplary drawing
 
1. A driving device for driving a motor including a rotor having a neodymium rare earth permanent magnet, principal ingredients of which are neodymium, iron and boron, the driving device comprising:
an inverter to perform field weakening control for the motor, thereby driving the motor at a variable speed;
a first detector to output a first detection signal corresponding to a motor drive current supplied to the motor by the inverter;
a second detector to output a second detection signal corresponding to a driving state of the motor; and
circuitry to set an overcurrent protection level and to control the inverter, wherein
immediately after the motor drive current corresponding to the first detection signal exceeds the overcurrent protection level, the circuitry executes first control to reduce the motor drive current, and
when the circuitry reduces the overcurrent protection level to a new current level, based on the second detection signal, the circuitry executes second control to reduce the motor drive current to a level lower than the new current level, wherein immediately after the motor drive current corresponding to the first detection signal exceeds the overcurrent protection level, the circuitry executes first control to reduce the motor drive current, and when the circuitry reduces the overcurrent protection level to a new current level, based on the second detection signal, the circuitry executes second control to reduce the motor drive current to a level lower than the new current level, wherein
the circuitry previously stores a plurality of current levels and selects one current level among the plurality of current levels as the overcurrent protection level, and
the circuitry controls a converter so that a maximum value Vd(n) of the bus voltage when setting the overcurrent protection level at l(n) and a maximum value Vd(n+1) of the bus voltage when setting the overcurrent protection level at l(n+1) satisfy Vd(n) Vd(n+1), where
N represents a predetermined integer,
n represents an integer larger than or equal to 1 and smaller than or equal to N,
l(n) represents each of the plurality of current levels, and
l(n)>l(n+1).