Control Method - Mitsubishi Electric FR-A820-00046 (0.4K) Instruction Manual

5.2

Control method

V/F control (initial setting), Advanced magnetic flux vector control, Real sensorless vector control, Vector control, and PM
sensorless vector control are available with this inverter.
 V/F control
The inverter controls the output frequency (F) and the output voltage (V) so that the ratio of frequency to voltage (V/F) is kept
constant when the frequency is changed.
 Advanced magnetic flux vector control
The inverter performs vector calculation and divide its output current into the excitation current and the torque current. The
inverter compensates the frequency and the voltage to output a current that meets the load torque to the motor, which improves
the motor torque at low speed. The output frequency is further compensated (slip compensation) to bring the actual motor
speed closer to the commanded speed. This control method is useful when the load fluctuates are severe.
NOTE
• Advanced magnetic flux vector control requires the following conditions.
If these conditions are not satisfied, select V/F control. Otherwise, malfunctions such as insufficient torque, uneven rotation
may occur.
• For the motor capacity, the rated motor current should be equal to or less than the rated inverter current. (It must be 0.4 kW
or higher.)
If a motor with substantially low rated current compared with the inverter rated current, however, is used, speed and torque
accuracies may deteriorate due to torque ripples, etc. Set the rated motor current to about 40% or higher of the inverter rated
current.
• The motor described in the following table is used.
Mitsubishi Electric standard motor (SF-JR)
Mitsubishi Electric high-efficiency motor (SF-
HR)
Mitsubishi Electric constant-torque motor (SF-
JRCA 4P, SF-HRCA)
Mitsubishi Electric high-performance energy-
saving motor (SF-PR)
Other motor (Mitsubishi motor SF-TH, etc. or
other manufacturer's motor)
• Single-motor operation (one motor to one inverter) is performed.
• The wiring length from inverter to motor is 30 m or less. (When the wiring length exceeds 30 m, perform offline auto tuning with
the wiring in place.)
• A sine wave filter (MT-BSL/BSC) is not used.
 Real sensorless vector control
• As the inverter estimates the motor speed and controls the output current more accurately, a high-level control of the speed
and the torque is enabled. Select Real sensorless vector control for a high-accuracy, fast-response control. The offline auto
tuning is required initially.
• This control method is useful for the following purposes:
- To minimize the speed fluctuation even at a severe load fluctuation
- To generate a low speed torque
- To prevent machine from damage due to a too large torque (To set the torque limit)
- To control the torque
NOTE
• Real sensorless vector control requires the following conditions.
If these conditions are not satisfied, select V/F control. Otherwise, malfunctions such as insufficient torque, uneven rotation
may occur.
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5. PARAMETERS
5.2 Control method
Motor
The offline auto tuning is not required.
The offline auto tuning is required.
Condition