Droop Control (Pr. 286 To Pr. 288) - Mitsubishi Electric FR-A700 Instruction Manual

Special operation and frequency control

4.25.4 Droop control (Pr. 286 to Pr. 288)

This function is designed to balance the load in proportion to the load torque to provide the speed drooping
characteristic under advanced magnetic flux vector control, real sensorless vector control and vector control.
This function is effective for balancing the load when using multiple inverters
Parameter
Name
Number
286 Droop gain
287 Droop filter time constant
Droop function activation
288
selection
-100%
When Pr. 288 = "0 to 2", or under advanced magnetic flux vector control
Droop compensation frequency
When Pr. 288 = "10, 11"
Droop compensation frequency
REMARKS
Set the droop gain to about the rated slip of the motor.
Synchronous speed at base frequency - Rated speed
Rated slip =
370
Initial
Value
0%
0.3s
0
Frequency
Droop compensation
frequency
0
Amount of torque current after filtering
=
Rated value of torque current
Amount of torque current after filtering
=
Rated value of torque current
Synchronous speed at base frequency
Magnetic flux Magnetic flux Magnetic flux Sensorless Sensorless Sensorless
Setting
Range
0 Normal operation
Droop control is valid
0.1% to
Set the drooping amount at the rated torque as a
100%
percentage with respect to the rated motor frequency.
Set the time constant of the filter applied on the torque
0 to 1s
amount current.
Droop control is not exercised during acceleration/
0
deceleration.
Droop control is always exercised during operation. (with
1
0 limit)
Droop control is always exercised during operation.
2
(without 0 limit)
Droop control is not exercised during acceleration/
10
deceleration. (Motor speed is referenced)
Droop control is always exercised during operation.
11
(Motor speed is referenced)
(1) Droop control
· The output frequency is changed according to
the magnitude of torque amount current under
advanced magnetic flux vector control, real
Droop
sensorless vector control and vector control.
gain
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.
Torque
100%
· The maximum droop compensation frequency
is 120Hz.
Rated motor frequency
×
Motor speed
×
×
100[%]
Vector Vector Vector
Description
×
Droop gain
100
×
Droop gain
100