A magnetic pole position detecting device for detecting a position of the magnetic pole of the rotor in a permanent magnet synchronous motor

摘要

A magnetic pole position detecting device (30) has a calculating unit (42) for correcting a magnetic pole position detected by a magnetic pole position detecting unit (50). In the magnetic pole position detecting unit, an additional phase amount is added to the position of the magnetic pole detected by the magnetic pole position detecting unit to move the rotor. With respect to a movement amount before and after this movement, a movement amount detected by the magnetic pole position determining unit is compared with an amount of movement detected by an encoder. If the difference between these values is greater than a predetermined limit, the process of detecting the position of the magnetic pole is determined as a wrong determination.