Mitsubishi Electric FR-A700 Technical Manual page 360

2.19.3 Droop control [Pr. 286 to 288]
Droop control makes the load balanced in proportion to the
load torque and provides droop characteristic to the speed
under Advanced magnetic flux vector control, Real
sensorless vector control (only in
control (only in ).
A700
[Pr.] Name
286 Droop gain
287 Droop filter time constant
Droop function activation
288
selection
Advanced Magnetic Flux Vector Control
[Pr. 288]
Operation frequency after
Setting
limit compensation is
0
1
Not
performed
during
2 command is limited
acceleration/
deceleration
10
11
The output frequency is changed according to the
magnitude of torque current under Advanced magnetic flux
vector control and Real sensorless vector control.
By setting [Pr. 288 ] in
A700
Real sensorless vector control and vector control can be
changed.
The drooping amount at the rated torque is set by the droop
gain as a percentage using the rated frequency (motor
speed when [Pr. 288 = 10, 11]) as a reference.
Set the droop gain to about the rated slip of the motor.
(Synchronous speed at
Rated base frequency)
=
Synchronous speed at base frequency
slip
The maximum value
compensation is either 120Hz or [Pr. 1 Maximum frequency],
whichever is smaller.
When [Pr. 288 = 0 to 2] or under Advanced magnetic flux vector control
Droop compensation frequency =
When [Pr. 288 = 10, 11]
Droop compensation frequency =
), and vector
A700
Initial Setting
Value Range
0
0% 0.1% to
100%
0.3s 0 to 1s
0 0 to 5
When the
Droop
Compensation
reference
negative
Frequency
Rated motor
frequency
at 0.5Hz
, droop control operation under
Rated
-
speed
×
100 [%]
of frequency after
Torque current after filtering
Rated value of torque current
Torque current after filtering
Rated value of torque current
A700 E700
(A700
This function is effective for balancing the load when using
multiple inverters
Description
Normal operation (droop control is invalid)
Droop control is valid
Set the drooping amount at the rated torque as a
percentage with respect to the rated motor frequency.
Set the time constant of the filter applied on the torque
current.
When the frequency after droop control operation limit
and droop compensation is negative, droop
compensation reference can be selected.
Real Sensorless Vector Control, Vector Control
Operation limit
Not performed
Frequency command is limited at
during acceleration/
deceleration
Frequency command is limited at
Always operates
Under vector control:
Frequency command is not limited
Always operates (rotation direction is inversed)
Under Real sensor less vector control:
Frequency command is limited at 0Hz
Not performed
Frequency command is limited at
during acceleration/
deceleration
Frequency command is limited at
Always operates
-100%
droop
Rated motor frequency
×
Motor speed
×
394
PARAMETER
When the frequency after
compensation is negative
0Hz
0Hz
0Hz
0Hz
Frequency
Droop compensation
frequency
0
×
Droop gain
100
×
Droop gain
100
Available
Inverters
A700 E700
—
Droop
compensation
reference
Rated motor
frequency
Rated motor
frequency
Rated motor
frequency
Motor speed
Motor speed
Droop
gain
Torque
100%