| 摘要 |
PURPOSE:To improve productivity by a constitution wherein a rotor is placed at a desired rotary position at the starting time to generate flux in specific direction on the stator side and absolute positional information per single revolution of rotor and positional information of rotor pole required for torque control are obtained simultaneously. CONSTITUTION:When a stator 12 is excited to generate flux PHI, the flux PHIinteracts with a rotor pole PHI to cause clockwise rotation of a rotor 11. When the absolute reference position (z) in the rotational direction of the rotor 11 matches with the position of phase Z, count of a position detector 2 is reset to 0 thus establishing the absolute position for single revolution of the rotor 11. When the rotor 11 rotates furthermore and the rotor pole PHI makes an angle 180 deg. to the stator flux PHI, the rotor 11 stops. A controller 6 detects stoppage of the rotor 11 and reads out a rotary angle theta0 at that time. The rotary angle theta0 corresponds to a rotary angle from a time point when the rotational direction absolute position (z) of the rotor passes through phase Z to the stop position of the rotor. The rotary angle theta0 is shifted by just 180 deg. from the phase of current inducing the flux in PHI direction. According to the method, direction PHIof the pole of the rotor can be known. |
