Digitax HD M753 Control User Guide
87
Issue Number: 3
Pr 00.038 {04.013} / Pr 00.039 {04.014}
Current Loop Gains
The current loop gains proportional (Kp) and integral (Ki) gains control the response of the current loop to a change in current (torque) demand. The default
values give satisfactory operation with most motors. However, for optimal performance in dynamic applications it may be necessary to change the gains to
improve the performance. The
Current Controller Kp Gain
(00.038) is the most critical value in controlling the performance. The values for the current loop
gains can be calculated by performing a stationary or rotating autotune (see
Autotune
Pr 00.040, earlier in this table) the drive measures the
Stator
Resistance
(05.017) and
Transient Inductance
(05.024) of the motor and calculates the current loop gains.
This will give a step response with minimum overshoot after a step change of current reference. The proportional gain can be increased by a factor of 1.5
giving a similar increase in bandwidth; however, this gives a step response with approximately 12.5 % overshoot. The equation for the integral gain gives a
conservative value. In some applications where it is necessary for the reference frame used by the drive to dynamically follow the flux very closely (i.e. high
speed Sensorless RFC-A induction motor applications) the integral gain may need to have a significantly higher value.
Summary of Contents for Digitax HD M753 EtherCAT
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