YASKAWA A1000 Series Quick Start Manual page 162

4.6 Basic Drive Setup Adjustments
Setting 2: Intelligent Stall Prevention
The drive adjusts the deceleration rate to maintain the DC bus voltage at the level set to parameter L3-17. The drive ignores
the selected deceleration time and uses the shortest possible deceleration time that will not cause the motor to stall.
This function uses the following parameters for adjusting the deceleration rate:
• DC bus voltage gain (L3-20)
• Deceleration rate calculations gain (L3-21)
• Inertia calculations for motor acceleration time (L3-24)
• Load inertia ratio (L3-25)
Note: The deceleration time is not constant. Do not use Intelligent Stall Prevention in applications where stopping accuracy is a concern. Use
dynamic braking options instead.
Setting 3: Stall Prevention with Dynamic Braking Option
Enables the Stall Prevention function while using a dynamic braking resistor. Overvoltage problems in the DC bus can occur
if Stall Prevention during deceleration is disabled (L3-04) in OLV and a dynamic braking option is installed. Set L3-04 to 3
to remedy this situation.
Setting 4: Overexcitation Deceleration 1
Decelerates with the set deceleration rate in an overexcitation state (increasing the motor flux). The motor will decelerate when
Stall Prevention is disabled (L3-04). Setting 4 changes the selected decel time and functions to provide protection from an
overvoltage trip.
Setting 5: Overexcitation Deceleration 2
Overexcitation Deceleration 2 slows down the motor while trying to maintain the DC bus voltage at the level set to parameter
L3-17. This function shortens the achievable deceleration time more than by using Overexcitation Deceleration 1. Setting 5
will shorten/lengthen the decel time to maintain the L3-17 bus level.
n L3-05: Stall Prevention Selection during Run
Determines how Stall Prevention works during Run. Stall Prevention during run prevents the motor from stalling by
automatically reducing the speed when a transient overload occurs while the motor is running at constant speed.
No.
L3-05
Note: 1. This parameter is available in V/f, V/f w/PG, and OLV/PM.
2. Stall Prevention during run is disabled when the output frequency is 6 Hz or lower regardless of the L3-05 and L3-06 settings.
Setting 0: Disabled
Drive runs at the set frequency reference. A heavy load may cause the motor to stall and trip the drive with an oC or oL fault.
Setting 1: Decelerate Using C1-02
If the current exceeds the Stall Prevention level set in parameter L3-06, the drive will decelerate at decel time 1 (C1-02). When
the current level drops below the value of L3-06 minus 2% for 100 ms, the drive accelerates back to the frequency reference
at the active acceleration time.
Setting 2: Decelerate Using C1-04
Same as setting 1 except the drive decelerates at decel time 2 (C1-04).
162
Output Frequency
specified deceleration time
Figure 4.36 Stall Prevention During Deceleration
Name
Stall Prevention Selection During Run
YASKAWA ELECTRIC TOEP C710616 41G YASKAWA AC Drive - A1000 Quick Start Guide
Deceleration characteristics
when Stall Prevention was
triggered during deceleration
Time
Setting Range
0 to 2
Default
1