Droop Control - Mitsubishi Electric 800 Series Instruction Manual

15.11

Droop control

Magnetic flux Sensorless Sensorless Sensorless
Magnetic flux Magnetic flux
This is a function to give droop characteristics to the speed by balancing the load in proportion with the load torque during the
Advanced magnetic flux vector control, Real sensorless vector control, and PM sensorless vector control.
This is effective in balancing the load when multiple inverters are connected.
Pr.
286
Droop gain
G400
287
Droop filter time constant
G401
 Droop control
• Droop control is enabled under Advanced magnetic flux vector control, Real sensorless vector control, and PM sensorless
vector control.
• In the droop control, the speed command changes depending on the amount of the current for torque.
Rated frequency
• The droop compensation frequency is calculated as follows.
Droop compensation frequency =
When the output frequency is equal to or lower than the rated frequency set in Pr.84: K = 1
When the output frequency is higher than the rated frequency set in Pr.84: K =
• The droop compensation frequency is limited as follows.
Control
Advanced magnetic flux vector control
Real sensorless vector control
(PM sensorless vector control)
NOTE
• Set the droop gain equivalent to the rated slip of the motor.
Rated slip =
• Droop control is disabled in the following conditions:
During DC injection brake operation, during PID control, during stall prevention operation, during traverse operation
Parameters referred to
Pr.1 Maximum frequencypage 211
Pr.178 to Pr.189 Input terminal function selection
394
15. (G) Control Parameters
15.11 Droop control
PM PM PM
Name Initial value Setting range
0%
0.3 s
Frequency
-100%
Current for torque after filtering
Rated torque current
400 Hz or Pr.1 Maximum frequency, whichever is smaller
Maximum motor frequency or Pr.1 Maximum frequency,
whichever is smaller
Synchronized speed at the time of base frequency - rated rotation speed
Synchronized speed at the time of base frequency
page 283
0 Normal operation
Droop control enabled.
0.1% to 100% Set the droop amount at the time of rated torque as % value of
the rated motor frequency.
0 to 1 s Set the time constant of the filter relative to the torque current.
Droop compensation
frequency
0 100%
Pr.84 Rated motor frequency × Pr.286 Droop gain
× K ×
Rated frequency (Pr.84)
Output frequency
Upper limit
Description
Droop
gain
Torque
100
Lower limit
0.5 Hz
0 Hz
10% of rated motor frequency
× 100[%]