Mitsubishi Electric 800 Series Instruction Manual page 137

Control method
• Speed control
Speed control operation is performed to zero the difference between the speed command (ω
detected by encoder (ω
as a torque current command (i
• Torque current control
A voltage (V ) is calculated to flow a current (i
q
controller.
• Magnetic flux control
The magnetic flux (Ф ) of the motor is derived from the excitation current (id). The excitation current command (i
2
calculated to use that motor magnetic flux (Ф
• Excitation current control
A voltage (V ) is calculated to flow a current (i
d
• Output frequency calculation
Motor slip (ωs) is calculated on the basis of the torque current value (i
is found by adding that slip (ωs) to the feedback (ω
The above results are used to make PWM modulation and run the motor.
136
PARAMETERS
). At this time, the motor load is found and its result is transferred to the torque current controller
FB

).
q
) which is identical to the torque current command (i
q
) as a predetermined magnetic flux.
2
) which is identical to the excitation current command (i
d
) and magnetic flux (Ф
q
) found by a feedback from the encoder.
FB

) and actual rotation value

) found by the speed
q

) is
d

).
d
). The output frequency (ω
2
)
0