| 摘要 |
PROBLEM TO BE SOLVED: To prevent a compressor from failing to start due the fact that a rotor cannot start to rotate against load torque.SOLUTION: When receiving stop command for an electric compressor 1 performing sensorless operation, speed command for the electric compressor 1 is set at zero so as to stop rotation of a rotor 3e of a compressing mechanism 3 by the electric motor 5. Then, during opposite rotation of the rotor 3e generated by differential pressure between refrigerant in a discharge chamber 7a and refrigerant in a suction chamber 7b, a rotation angle of the electric motor 5 is estimated so as to find out a rotation angle of the rotor 3e. Further, when the rotor 3e reached a predetermined rotation angle with low load torque, the opposite rotation of the rotor 3e is stopped and then stayed there by brake control that applies braking force to the electric motor 5. This allows the rotor 3e to rotate first at the rotation angle with low load torque when starting the electric compressor 1.SELECTED DRAWING: Figure 1 |
