Mitsubishi Electric FR-A700 Instruction Manual page 693

Parameter
When Pr. 288 = "0 to 2", or under advanced magnetic flux vector control, the droop compen-
sation frequency can be found with the following formula.
Droop compensation frequency
Use the following formula for the droop compensation frequency when Pr. 288 = "10 or 11".
Droop compensation frequency
NOTES Set the droop gain to about the rated slip of the motor.
Rated slip
Limit the frequency after droop compensation (0 limit)
Setting Pr. 288 under real sensorless vector control or vector control can limit the frequency
command when the frequency after droop compensation is negative.
Pr. 288
setting
0
(Initial value)/
10
1/11
2
Tab. 6-175: Setting of parameter 288
NOTE
The maximum value of frequency after droop compensation is either 120Hz or Pr. 1 "Maxi-
mum frequency", whichever is smaller.
FR-A700 EC
Torque current after filtering
= -------------------------------------------------------------------------------- -
Rated value of base frequency
Torque current after filtering
-------------------------------------------------------------------------------- -
=
Rated value of base frequency
Synchronous speed at base frequency Rated speed
--------------------------------------------------------------------------------------------------------------------------------------------- -
=
Synchronous speed at base frequency
Description
Under advanced magnetic flux vector control
Droop control is not exercised during accelera-
tion/deceleration.
Note that the frequency command after droop
control is limited at 0.5Hz when the frequency
command after droop control is negative.
Droop compensation amount is determined
using the rated motor frequency as reference.
×
Rated motor frequency Droop gain
×
----------------------------------------------------------------------------------------------- -
100
×
Motor speed Droop gain
×
-------------------------------------------------------------------- -
100
–
Under real sensorless vector control or
vector control
Droop control is not exercised during accelera-
tion/deceleration.
Note that the frequency command is limited at
0Hz when the frequency command after droop
control is negative.
When Pr. 288 = "10", droop compensation
amount is determined using the motor speed as
reference.
Droop control is always exercised during
operation.
Note that the frequency command is limited at
0Hz when the frequency command after droop
control is negative.
When Pr. 288 = "11", droop compensation
amount is determined using the motor speed as
reference.
Droop control is always exercised during
operation.
Note that under vector control, the frequency
command is not limited at 0Hz even when the
frequency command after droop control is
negative.
(The frequency command is limited at 0Hz under
real sesorless vector control.)
Special operation
×
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