A power conversion device comprising: power conversion circuitry configured to perform a power conversion for outputting a driving power to an induction motor, wherein the induction motor comprises a rotor, a first group of primary coils (51, 52, 53), and a second group of primary coils (61, 62, 63) isolated from the first group of primary coils (51, 52, 53); and characterized by control circuitry configured to: receive a master command phase from a master power conversion device, wherein the master power conversion device controls a master power conversion circuitry to output a master driving power to the first group of primary coils (51, 52, 53), based on a master voltage command having the master command phase in a master rotating coordinate system for driving the rotor; generate a voltage command having a command phase in a rotating coordinate system based on a torque target value, wherein a rotating magnetic field for driving the rotor is generated to rotate with the rotating coordinate system; calculate a rotation phase of the rotating coordinate system based on a command phase difference between the master command phase and the command phase to reduce the command phase difference; and control the power conversion circuitry to output the driving power to the second group of primary coils (61, 62, 63), based on the rotation phase and the voltage command. power conversion circuitry configured to perform a power conversion for outputting a driving power to an induction motor, wherein the induction motor comprises a rotor, a first group of primary coils (51, 52, 53), and a second group of primary coils (61, 62, 63) isolated from the first group of primary coils (51, 52, 53); and characterized by control circuitry configured to: receive a master command phase from a master power conversion device, wherein the master power conversion device controls a master power conversion circuitry to output a master driving power to the first group of primary coils (51, 52, 53), based on a master voltage command having the master command phase in a master rotating coordinate system for driving the rotor; generate a voltage command having a command phase in a rotating coordinate system based on a torque target value, wherein a rotating magnetic field for driving the rotor is generated to rotate with the rotating coordinate system; calculate a rotation phase of the rotating coordinate system based on a command phase difference between the master command phase and the command phase to reduce the command phase difference; and control the power conversion circuitry to output the driving power to the second group of primary coils (61, 62, 63), based on the rotation phase and the voltage command. receive a master command phase from a master power conversion device, wherein the master power conversion device controls a master power conversion circuitry to output a master driving power to the first group of primary coils (51, 52, 53), based on a master voltage command having the master command phase in a master rotating coordinate system for driving the rotor; generate a voltage command having a command phase in a rotating coordinate system based on a torque target value, wherein a rotating magnetic field for driving the rotor is generated to rotate with the rotating coordinate system; calculate a rotation phase of the rotating coordinate system based on a command phase difference between the master command phase and the command phase to reduce the command phase difference; and control the power conversion circuitry to output the driving power to the second group of primary coils (61, 62, 63), based on the rotation phase and the voltage command.