US 4,734,633 AGranted

Speed control apparatus for a synchronous motor

AssigneesToei Denki Kabushiki Kaisha, Toshiba Kikai Kabushiki Kaisha

InventorsTadahiro Ono, Naoshi Miura

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Abstract

A speed control apparatus for a synchronous motor is provided with a resolver fixedly connected to a rotor of the motor, which produces a phase modulated signal corresponding to an angular position of revolving magnetic field in the motor, a circuit for converting the phase modulated signal into a rotational speed signal of the motor, a phase compensation circuit for advancing in phase a reference signal in accordance with the rotational speed signal, a multiplier for multiplying the phase modulated signal and a rotational speed instruction signal, a synchronous rectifier for synchronously rectifying the output of the multiplier by an output of the phase compensation circuit, and a current control loop circuit for receiving an output of the synchronous rectifier and for producing a signal having a phase angle delayed as much as the phase angle is advanced in the phase compensation circuit.

Claims10

Dependent claims

A speed control apparatus for a synchronous motor comprising:

means for designating a rotational speed of the motor;
means for producing an angular position signal with respect to an angular position of a revolving magnetic field corresponding to that of a rotor on the motor;
means for producing an armature current command signal in accordance with a speed instruction supplied from said speed designating means and said angular position signal supplied from said angular position signal producing means;
rotational speed signal producing means responsive to said angular position signal for producing a speed signal corresponding to the speed of said motor;
phase compensation means responsive to said speed signal for advancing a phase of said armature current command signal with respect to the angular position of said rotor of the motor;
and
means for producing a desired armature current on armature windings of the motor including a current control loop circuit responsive to said phase-advanced armature current command signal for outputting said desired armature current.

4 more elements

Dependencies are inferred from the claim text.