B6: Dwell Function - YASKAWA AC Drive-A1000 Technical Manual

5.2 b: Application
Goal
Suppress long cycle oscillations
(longer than the integral time
setting)
Suppress short cycle oscillations
u

b6: Dwell Function

The Dwell function temporarily holds the frequency reference at a predefined value for a set time then continues accelerating
or decelerating.
The Dwell function helps prevent speed loss when starting and stopping a heavy load with induction motors. When 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 and
reduce the starting current.
The figure below illustrates how the Dwell function works.
Note: Set the stopping method to "Ramp to Stop" (b1-03 = 0) to use the Dwell function.
n b6-01, b6-02: Dwell Reference, Dwell Time at Start
Parameter b6-01 determines the frequency that is held for the time set in b6-02 during acceleration.
No.
b6-01
b6-02
n 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.
No.
b6-03
b6-04
150
Tuning Procedure
• Increase the integral time (b5-03)
• If oscillation cycle time is close to
the derivative time, reduce the
derivative time (b5-05).
• If the derivative time is set to 0.00 s
and oscillations are still a problem,
reduce the proportional gain (b5-02)
or increase the PID primary delay
time (b5-08)
OFF
Run Command
Output Frequency
b6-02
Figure 5.25 Dwell Function at Start and Stop
Name
Dwell Reference at Start
Dwell Time at Start
Name
Dwell Reference at Stop
Dwell Time at Stop
YASKAWA ELECTRIC SIEP C710616 31B YASKAWA AC Drive – A1000 Technical Manual
Response
Response
ON OFF
b6-01
b6-03
b6-04
Setting Range
0.0 to 400.0 Hz
Setting Range
0.0 to 400.0 Hz
Result
Before adjustment
After adjustment
After adjustment
Before adjustment
0.0 to 10.0 s
0.0 to 10.0 s
Time
Time
Default
0.0 Hz
0.0 s
Default
0.0 Hz
0.0 s