Справочник Пользователя для Mitsubishi Electronics FR-A700

(1) Speed control

Speed control operation is performed to zero the difference between the speed command (

ω*) and actual rotation

detection value (

ωFB). At this time, the motor load is found and its result is transferred to the torque current

controller as a torque current command (iq*).

(2) Torque current control

A voltage (Vq) is calculated to start a current (iq*) which is identical to the torque current command (iq) found by
the speed controller.

(3) Magnetic flux control

The magnetic flux (

φ2) of the motor is derived from the excitation current (id). The excitation current command (id*)

is calculated to use that motor magnetic flux (

φ2) as a predetermined magnetic flux.

(4) Excitation current control

A voltage (Vd) is calculated to start a current (id) which is identical to the excitation current command (id*) found by
magnetic flux control.

(5) Output frequency calculation

Motor slip (

ωs) is calculated on the basis of the torque current value (iq) and magnetic flux (φ2). The output

frequency (w0) is found by adding that slip (

ωs) to the feedback (ωFB) found by a feedback from the encoder.

The above results are used to make PWM modulation and run the motor.