4.6 Selecting the Motor Control Method
4-7
4.6 Selecting the Motor Control Method
FRENIC-MEGA supports the following motor control methods.
Refer to “4.7 Performance Comparison for Drive Controls (Summary)” for details on the features of each
control method.
Table 4.6-1
V/f control with slip
compensation inactive
Dynamic torque vector control
Frequency control
with slip
compensation
V/f control with slip
compensation active
Frequency control
with ASR (Auto
speed regulator)
Dynamic torque vector control
with sensor
Sensorless vector control
Speed control
with automatic
speed regulator
(ASR)
Vector control with sensor
Sensorless vector control
Vector control with sensor
4.6.1 V/f control without slip compensation (induction motors)
Under this control, the inverter controls a motor with the voltage and frequency according to the V/f pattern
specified by function codes. This control disables all automatically controlled features such as the slip
compensation, so no unpredictable output fluctuation occurs, enabling stable operation with constant output
frequency.
4.6.2 V/f control with slip compensation (induction motors)
Applying any load to an induction motor causes a rotational slip due to the motor characteristics, decreasing the
motor rotation. The inverter’s slip compensation function first presumes the slip value of the motor based on the
motor torque generated and raises the output frequency to compensate for the decrease in motor rotation. This
prevents the motor from decreasing the rotation due to the slip. That is, this function is effective for improving the
motor speed control accuracy.
The compensation value is specified by combination of function codes P12* (Rated slip frequency), P09* (Slip
compensation gain for driving) and P11* (Slip compensation gain for braking).
Function code H68* enables or disables the slip compensation function according to the motor driving conditions.
Table 4.6-2
Motor driving frequency zone
To Next Page
Loading...
