Control Mode - Mitsubishi Electric FR-A700 Instruction Manual

Control mode

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.
POINT
If the following conditions are not satisfied, select V/F control since malfunction such as insufficient torque and uneven
rotation may occur.
· The motor capacity should be equal to or one rank lower than the inverter capacity. (note that the capacity should be
0.4kW or more)
· Motor to be used is any of Mitsubishi standard motor, high efficiency motor (SF-JR, SF-HR two-pole, four-pole, six-pole
0.4kW or more) or Mitsubishi constant torque motor (SF-JRCA, SF-HRCA 200V class four-pole 0.4kW to 55kW). When
using a motor other than the above (other manufacturer's motor, SF-TH, etc.), perform offline auto tuning without fail.
· Single-motor operation (one motor run by one inverter) should be performed.
· Wiring length from inverter to motor should be within 30m (98.4feet). (Perform offline auto tuning in the state where
wiring work is performed when the wiring length exceeds 30m (98.4feet).)
(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
POINT
If the following conditions are not satisfied, select V/F control since malfunction such as insufficient torque and uneven
rotation may occur.
· The motor capacity should be equal to or one rank lower than the inverter capacity. (note that the capacity should be
0.4kW or more)
· Perform offline auto tuning without fail. Offline auto tuning is necessary under real sensorless vector control even when
the Mitsubishi motor is used.
· Single-motor operation (one motor run by one inverter) should be performed.
(4) Vector control
⋅ When the FR-A7AP is mounted, 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 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 torque at zero speed (i.e. status of motor shaft = stopped)
POINT
If the conditions below are not satisfied, malfunction such as insufficient torque and uneven rotation may occur.
· The motor capacity should be equal to or one rank lower than the inverter capacity. (note that the capacity should be
0.4kW or more)
· Motor to be used is any of Mitsubishi standard motor with encoder, high efficiency motor with encoder (SF-JR, SF-HR
two-pole, four-pole, six-pole 0.4kW or more) or Mitsubishi constant torque motor with encoder (SF-JRCA, SF-HRCA
200V class four-pole 0.4kW to 55kW) or vector control dedicated motor (SF-V5RU). When using a motor other than the
above (other manufacturer's motor), perform offline auto tuning without fail.
· Single-motor operation (one motor run by one inverter) should be performed.
· Wiring length from inverter to motor should be within 30m (98.4feet). (Perform offline auto tuning in the state where
wiring work is performed when the wiring length exceeds 30m (98.4feet).)
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