Special operation and frequency control
4.21.3 Droop control (Pr. 286 to Pr. 287)
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.
This function is effective for balancing the load when using multiple inverters.
Droop filter time
Set the droop gain to about the rated slip of the motor.
Droop control is invalid during PID control operation.
The maximum value of frequency after droop compensation is either 120Hz or Pr. 1 Maximum frequency, whichever is smaller.
Parameters referred to
Pr. 1 Maximum frequency
Refer to page 246
Torque current after filtering
Rated value of torque current
Synchronous speed at base frequency - rated speed
Synchronous speed at base frequency
Refer to page 96
Droop control is invalid (Normal operation)
Droop control is valid
Drooping amount at the rated torque as a percentage with
respect to the rated motor frequency.
0 to 1s
Time constant of the filter applied on the torque current.
The output frequency is changed according to
the magnitude of torque current under
Advanced magnetic flux vector control.
The drooping amount at the rated torque is set
by the droop gain as a percentage using the
rated frequency as a reference.
The maximum droop compensation frequency
Pr. 84 Rated motor frequency × Pr. 286 Droop gain