US 12,341,447 B2
Power conversion device
Kazuaki Tobari, Tokyo (JP); Yusaku Onuma, Tokyo (JP); Takuya Sugimoto, Tokyo (JP); Hiroshi Watanabe, Tokyo (JP); and Mutsuo Tokashiki, Tokyo (JP)
Assigned to Hitachi Industrial Equipment Systems Co., Ltd., Tokyo (JP)
Appl. No. 18/021,220
Filed by Hitachi Industrial Equipment Systems Co., Ltd., Tokyo (JP)
PCT Filed Jun. 14, 2021, PCT No. PCT/JP2021/022592
§ 371(c)(1), (2) Date Feb. 14, 2023,
PCT Pub. No. WO2022/054357, PCT Pub. Date Mar. 17, 2022.
Claims priority of application No. 2020-151558 (JP), filed on Sep. 9, 2020.
Prior Publication US 2023/0299700 A1, Sep. 21, 2023
Int. Cl. H02P 21/16 (2016.01); H02P 21/22 (2016.01)
CPC H02P 21/16 (2016.02) [H02P 21/22 (2016.02); H02P 2207/05 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A power conversion device controlling a magnet motor, comprising:
a controller configured to:
calculate a first power based on an output voltage and an output current of the magnet motor,
calculate a second power based on an electric circuit coefficient, a current command, an output frequency, and an induced voltage coefficient of the magnet motor,
estimate the induced voltage coefficient so that the first power follows the second power,
control driving of the magnet motor in accordance with the induced voltage coefficient, wherein
the controller calculates the induced voltage coefficient so that a deviation between the first active power and the second active power is set to zero or so that a deviation between the first reactive power and the second reactive power is set to zero, on the basis of a relationship between the electric circuit coefficient and a frequency estimation value of the magnet motor,
perform proportional control and integration control so that the deviation between the first active power and the second active power is set to zero when the magnet motor is in a low speed region, and
perform the proportional control and the integration control so that a deviation between the first reactive power and the second reactive power is set to zero when the magnet motor is in a medium-high speed region.