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Yaskawa Sigma II Series SGMVH User Manual

Page 272

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9 Adjustments

9.4.5 Using the Mode Switch (P/PI Switching)

9-12

Using the Acceleration Level to Switch Modes

With this setting, the speed loop is switched to P
control when the motor’s acceleration rate exceeds
the acceleration rate set in parameter Pn10E.

„ 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 Error Pulse Level to Switch Modes

This setting is effective with position control only.
With this setting, the speed loop is switched to P control when
the error pulse exceeds the value set in parameter Pn10F.

„ 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

Motor acceleration

+Pn10E

Acceler-

ation 0
-Pn10E

PI control

PI control

PI

P

P

Overshoot

Without Mode Switching

With Mode Switching

Undershoot

Motor

speed

Time

Motor

speed

Time

Motor

speed

Reference

Speed

Pn10F

Position

error pulse

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