| 摘要 |
PROBLEM TO BE SOLVED: To promptly conduct slip-start of a permanent-magnet synchronous motor by an inverter. SOLUTION: This device is provided with a means, that turns on semiconductor-switching elements that make up an inverter 20 for short- circuiting at least two phases of armature windings, when a rotor is slipping; a means that makes all the switching elements turn off, after a short circuit operation; a current detector 41 that detects an armature current flowing, while the switching elements are turned off and a number of phases converter 42; a speed polarity detector 56a that detects speed polarity from the vector rotating direction of the armature current flowing during the turn-off period; a speed absolute value computing device 56b that computes a speed absolute value from the maximum value of the armature current flowing during the turn-off period; a multiplier 56c, that estimates the slip speed of the rotor from the speed polarity and the speed absolute value; and a position-estimating device 52, that estimates the magnetic pole position from the slip speed of the rotor and an integrator 45. |
