◆ b6: Dwell Function
The Dwell function is used to temporarily hold the frequency reference at a predefined value for a set time, then continue
accelerating or decelerating.
If used with induction motors, the Dwell function can help prevent speed loss when starting and stopping a heavy load. If
running a PM motor in V/f control, the pause in acceleration allows the PM motor rotor to align with the stator field of
the motor, thus reducing the starting current.
The figure below shows how the Dwell function works.
Note: Using the Dwell function requires that the stopping method for the drive be set to “Ramp to stop” (b1-03 = 0).
Figure 5.26
Figure 5.26 Dwell Function at Start and Stop
■ b6-01, b6-02: Dwell Reference, Dwell Time at Start
b6-01 determines the frequency that is held or the time set in b6-02 during acceleration.
■
b6-03, b6-04: Dwell Reference, Dwell Time at Stop
Parameter b6-03 determines the frequency that is held for the time set in b6-04 during deceleration.
Suppress long cycle oscillations (longer than
the integral time setting)
• Increase the integral time (b5-03)
Suppress short cycle oscillations
• If oscillation cycle time is close to the derivative
time, the derivative part is likely having too much
influence. Reduce the derivative time (b5-05).
• If the derivative time is set to 0.00 s and
oscillations are still a problem, try reducing the
proportional gain (b5-02) or try increasing the
PID primary delay time (b5-08)
No. Name Setting Range Default
b6-01
Dwell Reference at Start
0.0 to 400.0 Hz 0.0 Hz
b6-02
Dwell Time at Start
0.0 to 10.0 s 0.0 s
No. Name Setting Range Default
b6-03
Dwell Reference at Stop
0.0 to 400.0 Hz 0.0 Hz
b6-04
Dwell Time at Stop
0.0 to 10.0 s 0.0 s
Goal Tuning Procedure Result
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