YASKAWA CIMR-ZU A Series Programming Manual page 109

Settin 1 General Purpose Stall Pre ention
The drive tries to decelerate within the set deceleration time. The drive pauses deceleration when the DC bus voltage exceeds
the Stall Prevention level and then continues deceleration when the DC bus voltage drops below that level. Stall Prevention
may be triggered repeatedly to avoid an overvoltage fault. The DC bus voltage level for Stall Prevention depends on the input
voltage setting E1-01.
Dri e Input olta e
200 V Class
400 V Class
This method may lengthen the total deceleration time compared to the set value. If this is not appropriate for the application consider using
Note:
a dynamic braking option.
illustrates the function of Stall Prevention during deceleration.
Figure 1.64
Settin 2 Intelli ent Stall Pre ention
The drive adjusts the deceleration rate so the DC bus voltage is kept at the level set to parameter L3-17. This produces the
shortest possible deceleration time while protecting the motor from stalling. The selected deceleration time is disregarded and
the achievable deceleration time cannot be smaller than 1/10 of the set deceleration time.
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)
The deceleration time is not constant. Do not use Intelligent Stall Prevention in applications where stopping accuracy is a concern.
Note:
Settin O ere citation Deceleration 1
Overexcitation Deceleration 1 (increasing the motor flux) is faster than deceleration with no Stall Prevention (L3-04 = 0).
Setting 4 changes the selected decel time and functions to provide protection from an overvoltage trip.
Deceleration (Induction Motors) on page 126
Settin O ere citation 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.
for details.
Motors) on page 126
L Stall Pre ention Selection durin
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
Stall Prevention during run is disabled when the output frequency is 6 Hz or lower regardless of the L3-05 and L3-06 settings.
Note:
Settin 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.
Output Frequency
specified deceleration time
Fi ure 1 Stall Pre ention Durin Deceleration
for details.
Name
Stall Prevention Selection During Run
Stall Pre ention Le el durin Deceleration
377 Vdc
754 Vdc
Deceleration characteristics
when Stall Prevention was
triggered during deceleration
Refer to Overexcitation Deceleration (Induction
un
Settin
1 8 L Protection Functions
Time
Refer to Overexcitation
an e De ault
0 to 2
1
1
1