Chapter 12 Description of Parameter Settings|CFP2000 Series
12.1-07-10
Torque Compensation Gain (V/F and SVC control mode)
Factory Setting: 0
Settings 0~10
When the motor load is large, a part of drive output voltage is absorbed by the resistor of stator
winding and causes insufficient voltage at motor induction and result in over output current and
insufficient output torque. It can auto adjust output voltage by the load and keep the air gap
magnetic fields stable to get the optimal operation.
In the V/F control, the voltage will be decreased in direct proportion when the frequency is
decreased. It’ll cause decrease torque at low speed due to small AC resistor and the same DC
resistor. Therefore, Auto torque compensation function will increase the output voltage in the low
frequency to get higher start torque.
When Pr.07-26 is set to large, it may cause motor overflux and result in too large output current,
motor overheat or triggers protection function.
Slip Compensation Gain (V/F and SVC control mode)
Factory Setting: 0.00
(1 in SVC mode)
Settings 0.00~10.00
The induction motor needs the constant slip to produce magnetic torque. It can be ignore in the
higher motor speed, such as rated speed or 2-3% slip.
In the operation with variable frequency, the slip and the synchronous frequency will be in
reverse proportion to produce the same magnetic torque. That is the slip will be larger with the
reduction of synchronous frequency. The motor may stop when the synchronous frequency is
decreased to a specific value. Therefore, the slip serious affects the accuracy of motor speed at
low speed.
In another situation, when the drive uses with induction motor, the slip will be increased by the
increasing load. It also affects the accuracy of motor speed.
This parameter can be used to set compensation frequency and reduce the slip to close the
synchronous speed when the motor runs in the rated current to raise the drive accuracy. When
the drive output current is larger than Pr.05-05 No-load Current of Induction Motor 1 (A), the
drive will compensation the frequency by this parameter.
When the control method (Pr.00-11) is changed from V/f mode to vector mode, this parameter
will auto be set to 1.00. Otherwise, it will be set to 0.00. Please do the compensation of slip after
overload and acceleration. The compensation value should be increased from small to large
gradually. That is to add the output frequency with motor rated slip X Pr.07-27 Slip
Compensation Gain when the motor is rated load. If the actual speed ratio is slow than
expectation, please increase the setting. Otherwise, decrease the setting.
Reserved
To Next Page