Weakening of the field in synchronizer servo drives

Permanent magnet excited synchronous motors (PMSM) with feed from an intermediate circuit voltage inverter with pulse width modulation are used in large number for high dynamic controlled servo axes. In the traditional manner of operation with an oriented stator current at the rotor field the availability of the standing voltage of the inverter to the rotation and torque field is limited. With the weakened field operation it is possible to clearly increase the rotation at the same torque. At the same time through an aimed at current requirement in the stator winding the motor voltage drops to expand the range of rotation. A traditional field of use of weakening of the field operation is in winding applications. Up to now asynchronous motor use is preferred. The weakening of the field in synchronous motors now also opens these applications to permanent excited microspeed MCS servo motors with their especially small cogging torques. The discussion covers introduction; drives laid out smaller; operation without field weakening; field weakening over the stator winding; increase of the overall current flow; operating characteristics of drives in practice; advantages of field weakening; and summary.