Yaskawa Sigma II Series DC Power Input SGMAJ - Manual (Page 269)

9 Adjustments
9.4.4 Using the Mode Switch (P/PI Switching)
9-18
Using the Torque Reference Level to Switch Modes (Factory Setting)
With this setting, the speed loop is switched to P control when the
value of torque reference input exceeds the torque set in parameter
Pn10C. The factory default setting for the torque reference detection
point is 200% of the rated torque (Pn10C = 200).
„ Operating Example
If the mode switch function is not being used and the SERVOPACK is always operated with PI control, the speed of the
motor may overshoot or undershoot due to torque saturation during acceleration or deceleration. The mode switch function
suppresses torque saturation and eliminates the overshooting or undershooting of the motor speed.
Using the Speed Reference Level to Switch Modes
With this setting, the speed loop is switched to P control when the value
of speed reference input exceeds the speed set in parameter Pn10D.
„ Operating Example
In this example, the mode switch is used to reduce the settling time. It is necessary to increase the speed loop gain to reduce
the settling time. Using the mode switch suppresses overshooting and undershooting when speed loop gain is increased.
Motor speed
Reference speed
Speed
Torque reference
+Pn10C
Torque
reference 0
- Pn10C
PI control PI control PI P P
Overshoot
Without Mode Switching With Mode Switching
Undershoot
Motor
speed
Time
Motor
speed
Time
Speed reference
Speed
Pn10D
Motor
speed
Time
P control PI PI control
Motor speed
Speed
reference
Long settling time
Increase speed loop gain.
Settling time
Motor
speed
Overshoot
Undershoot
Motor
speed
Time
Motor
speed
Without Mode Switching With Mode Switching