Mitsubishi Electric FR-A700 Series, Technical Manual

Page: 222 / 550

256
PARAMETER
2.7.2 Simple magnetic flux vector control [Pr. 71, 80, 90]
(F700)
This control method improves the low speed torque when higher torque than V/F control is necessary in the low speed range.
Simple magnetic flux vector control can be selected by setting the capacity and type of the motor used.
(1) Conditions of Simple magnetic flux vector
control
Simple magnetic flux vector control may only be
utilized effectively when all of the following conditions
are satisfied.
If any of the conditions cannot be satisfied, torque
shortage, speed fluctuation or another fault may
occur.
(2) Selection method of Simple magnetic flux
vector control
Simple magnetic flux vector control is selected by
simply setting [
Pr. 80 Motor capacity
≠
9999]. When
[ Pr. 80 = 9999], V/F control is selected.
When using the Mitsubishi constant torque motor, set
[
Pr. 71 = 1].
Set the rated motor frequency in [ Pr. 3 ] and rated
motor voltage in [ Pr. 19 ] when Simple magnetic flux
vector control is selected.
When [
Pr. 19 ] is 9999 or 8888, motor voltage is
regarded as 200V (200V class) or 400V (400V class).
(3) Motor constants setting
Although it is usually unnecessary, set the motor
primary resistance value (R1) for connection in [
Pr.
90 ] when you need more torque under Simple
magnetic flux vector control for other manufacturer’s
motor.
When the setting is 9999 (initial value), set by
referring the motor constants of the Mitsubishi motor
(SF-JR, SF-HRCA) as standard.
(4) Slip compensation setting
Since output frequency compensation is not
performed under Simple magnetic flux vector control,
the actual speed decreases by the motor slip (during
driving load operation) if the load to the motor
increases.
Set the slip compensation if you want to keep the
actual speed constant even if the load to the motor
varies. Refer to page 391 for slip compensation.
[ Pr. ] Name
Initial
Value
Setting Range Description
71 Applied motor 0
0 Thermal characteristics of a standard motor
1
Thermal characteristics of the Mitsubishi constant-
torque motor
2
Thermal characteristics of a standard motor
Adjustable 5 points V/F (Refer to page 248)
20 Mitsubishi standard motor (SF-JR 4P 1.5kW or less)
80
Motor capacity
(Simple magnetic flux vector
control)
9999
55K or less 0.4 to 55kW
Set the capacity of the motor used to select Simple
magnetic flux vector control.
75K or more 0 to 3600kW
9999 V/F control is performed.
90 Motor constant (R1) 9999
55K or less 0 to 50
Ω
Used to set the motor primary resistance value.
(Usually setting is not necessary.)
75K or more 0 to 400m
Ω
9999 Uses the Mitsubishi motor (SF-JR, SF-HRCA) constants
F700
The motor capacity should be equal to or one
rank lower than the inverter capacity.
The number of motor poles should be 2, 4 or 6.
(Only 4 poles for constant-torque motor. Setting
is not necessary.)
Single-motor operation (one motor run by one
inverter) should be performed.
The wiring length from inverter to motor should
be within 30m