B6: Dwell Function - YASKAWA A1000 Series Technical Manual

Goal
Suppress long cycle oscillations (longer than
the integral time setting)
Suppress short cycle oscillations

◆ 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
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.
No.
b6-01
b6-02
■ 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
YASKAWA ELECTRIC SIEP C710616 27C YASKAWA AC Drive A1000 Technical Manual
Tuning Procedure
• Increase the integral time (b5-03)
• 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)
OFF
Run Command
Output Frequency
b6-02
Figure 5.26 Dwell Function at Start and Stop
Name
Dwell Reference at Start
Dwell Time at Start
Name
Dwell Reference at Stop
Dwell Time at Stop
Response
Response
OFF
ON
common_TMonly
b6-01
b6-03
b6-04
Setting Range
0.0 to 400.0 Hz
0.0 to 10.0 s
Setting Range
0.0 to 400.0 Hz
0.0 to 10.0 s
5.2 b: Application
Result
Before adjustment
After adjustment
Time
Before adjustment
After adjustment
Time
Default
0.0 Hz
0.0 s
Default
0.0 Hz
0.0 s
5
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