Mitsubishi Electric FR-A800, Instruction Manual

Page: 231 / 1042

Parameters Control method
FR-A800 5 - 51
Vector control
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With a vector control compatible option installed, full-scale vector control operation of a motor
with an encoder can be performed. Fast response/high accuracy speed control (zero speed
control, servo lock), torque control, and position control can be performed. With the FR-A8APR
installed, the vector control operation of a motor with a resolver can be performed.
●
What is vector control?
Vector control has excellent control characteristic compared to V/F control and other controls.
The control characteristic of the vector control is equal to those of DC machines.
This control method can be applied 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 (torque limit)
– To perform torque control or position control
– To control the torque at a servo-lock status (motor shaft stopped status)
NOTE Vector control requires the following conditions.
When the conditions are not satisfied, 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.)
Using a motor with the rated current substantially lower than the rated inverter current will
cause torque ripples, etc. and degrade the speed and torque accuracies. As a reference, select
the motor with the rated motor current that is about 40% or higher of the rated inverter cur-
rent.
●
The vector control of PM motors can be performed only when a PM motor with a resolver are
used together with the FRA8APR. Torque control is not available with a PM motor.
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The motor described in the table below is used.
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Single-motor operation (one motor to one inverter) is performed.
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The wiring length from inverter to motor is 30 m or less. (When the wiring length exceeds
30 m, perform offline auto tuning in a wired state.)
●
A surge voltage suppression filter (FR-ASF/FR-BMF) or sine wave filter (MT-BSL/BSC) is not used.
Motor Condition
Vector control dedicated motor (SF-V5RU 1500 r/min series)
Offline auto tuning is not
required
Mitsubishi standard motor with encoder (SF-JR)
Mitsubishi high-efficiency motor with encoder (SF-HR)
Mitsubishi constant-torque motor with encoder (SF-JRCA 4P, SF-HRCA)
Other motors (motors other than SF-V5RU 1500 r/min series, other
manufacturers' motors, etc.)
Offline auto tuning is required