Control Mode - Mitsubishi Electric FR-A720-0.4K Instruction Manual

4.3

Control mode

V/F control (initial setting), advanced magnetic flux vector control, real sensorless vector control and vector control are
available with this inverter.
(1) V/F Control
⋅ It controls frequency and voltage so that the ratio of frequency (F) to voltage (V) is constant when changing frequency.
(2) Advanced magnetic flux vector control
⋅ This control devides the inverter output current into an excitation current and a torque current by vector calculation
and makes voltage compensation to flow a motor current which meets the load torque.
(3) Real sensorless vector control
⋅ By estimating the motor speed, speed control and torque control with more advanced current control function are
enabled. When high accuracy and fast response is necessary, select the real sensorless vector control and
perform offline auto tuning and online auto tuning.
⋅ This control can be applied to the following applications.
⋅ To minimize the speed fluctuation even at at a severe load fluctuation
⋅ To generate low speed torque
⋅ To prevent machine from damage due to too large torque (torque limit)
⋅ To perform torque control
(4) Vector control
⋅ When the FR-A7AP is mounterd, full-scale vector control operation can be performed using a motor with encoder.
Fast response/high accuracy speed control (zero speed control, servo lock), torque control, and position control
can be performed.
⋅ What is vector control?
Excellent control characteristics when compared to V/F control and other control techniques, achieving the control
characteristics equal to those of DC machines.
It is suitable for applications below.
⋅ To minimize the speed fluctuation even at at a severe load fluctuation
⋅ To generate low speed torque
⋅ To prevent machine from damage due to too large torque (torque limit)
⋅ To perform torque control or position control
⋅ Servo-lock torque control which generates a torque at zero speed (i.e. status of motor shaft = stopped)
Control mode
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