Speed Estimation Gain And Current Control Gain (Pr.730, Pr.824, Pr.825) - Mitsubishi Electric FR-E700EX Instruction Manual

Speed control
4.4.7

Speed estimation gain and current control gain (Pr.730, Pr.824, Pr.825)

Adjust if any of phenomena such as unusual vibration, noise, or overcurrent is produced by the motor or machinery.

Parameter
Name
number
Speed estimation
730
P gain
Torque control P
824
gain
Torque control
825
integral time
(1) Speed control P gain 2 (Pr.730)
 Set the proportional gain for the speed estimator with 200 rad/s as 100%.
 Setting this parameter higher improves the trackability for speed command changes. It also reduces the speed
fluctuation caused by an external disturbance.
(2) Torque control P gain (Pr.824)
 The 100% current loop proportional gain is equivalent to 1000 rad/s.
 For general adjustment, make setting within the range 50 to 200% as a guideline.
 Set the proportional gain.
 Increasing the value improves trackability in response to a current command change and reduces current variation with
disturbance. However, a too large gain will cause instability, generating harmonic torque pulsation.
(3) Torque control integral time (Pr.825)
 Set the integral time of current control.
 Decreasing the value shortens the time taken to return to the original torque if current variation with disturbance occurs.
(4) Adjustment procedure
Usually, use Pr.820 and Pr.821 for adjustment of the speed control gain, and set "9999 (initial value)" in Pr.730, Pr.824, and
Pr.825.
Make adjustment when any of such phenomena as unusual motor and machine vibration/noise/current and overcurrent
has occurred.
1)Check the conditions and simultaneously change the Pr.824 value.
2)If you cannot make proper adjustment, change the Pr.825 value and repeat step 1).
Set Pr.824 a little lower and Pr.825 a little higher. First lower Pr.824 and check the motor for unusual vibration/noise and
overcurrent. If the problem still persists, increase Pr.825.
Decrease the value 10% by 10% until just before unusual noise and current are improved, and set about
0.8 to 0.9 of that value.
Pr.824
Note that a too low value will produce current ripples, causing the motor to generate sound synchronizing
the cycle of current ripples.
Increase the current value double by double until just before an unusual noise and current does not occur,
and set about 0.8 to 0.9 of that value.
Pr.825
Note that taking a too long time will produce current ripples, causing the motor to generate sound
synchronizing the cycle of current ripples.
86
Initial Setting
value range
0 to 300% Set the proportional gain for the speed estimator.
MM-GKR motor
9999
9999
S-PM geared
motor
0 to 200% Set the current loop proportional gain.
MM-GKR motor
9999
9999
S-PM geared
motor
0 to 50ms Set current loop integral compensation time.
MM-GKR motor
9999
9999
S-PM geared
motor
Adjustment Method
Description
The following value is set: 200% for 0.1K and 125% for
0.2K to 0.4K.
100% is set.
The following value is set: 200% for 0.1K and 150% for
0.2K to 0.4K.
50% is set.
The following value is set: 2.5ms for 0.1K and 6.7ms for
0.2K to 0.4K.
20.0ms is set.