MFA Series

Permanent Magnet Electrical Motors

ASSM: Adjustable-Speed Synchronous Machine

In adjustable-speed permanent-magnet synchronous machines, the rotor speed is controlled by adjusting the frequency of the input voltage. Unlike standard brushless permanent-magnet DC motors, this type of machine does not utilize position sensors.

Permanent magnets are mounted on the rotor of a permanent-magnet synchronous machine, which could be either inner or outer rotor type. The poly-phase armature winding is embedded in the stator, whose number of poles is the same as that of the rotor. The machine can operate as a generator or as a motor. When the machine operates as a motor, the stator poly-phase winding can be fed either by a sinusoidal AC source or by a DC source via a DC to AC inverter. When the machine operates as a generator, the stator poly-phase winding supplies an AC source for electric loads.