Mitsubishi Electric FR-A700 Series, Техническое руководство

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