YASKAWA SGMJV User Manual page 264

6 Adjustments
6.9.5 Using the Mode Switch (P/PI Switching)
<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.
Motor
rotational
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 Pn10D.
<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.
Increase speed loop gain
6-70
Without Mode Switching
Overshoot
Undershoot
Pn10D
Without Mode Switching
Speed reference
Motor
rotational
speed
Long Settling Time
Overshoot
Motor
rotational
speed
Undershoot
With Mode Switching
Motor
rotational
speed
Time
Speed reference
Speed
PI P Control
With Mode Switching
Motor
rotational
speed
Time
Motor
rotational
speed
Time
Time
Motor
rotational
speed
Time
PI Control
Time
Settling time