YASKAWA V1000 Technical Manual page 213

n L3-04: Stall Prevention Selection during Deceleration
Stall Prevention during deceleration can control the deceleration based on the DC bus voltage and prevent an overvoltage
fault caused by high inertia or rapid deceleration.
Selects the Stall Prevention method during deceleration.
No.
L3-04 Stall Prevention Selection During Deceleration Selection
<1> Settings 3 and 4 are not available in OLV/PM control mode.
<2> Setting 7 is available in drive software versions PRG: 1020 and later.
Setting 0: Disabled
When this setting is used, the drive decelerates according to the set deceleration time. With high inertia loads or rapid
deceleration, an overvoltage (ov) fault may occur. In this case use braking options or switch to another L3-04 selection.
Note: Use this setting or set L3-04 to 3 whenever a Dynamic Braking Resistor or another braking option is used.
Setting 1: General Purpose Stall Prevention
With this setting the drive tries to decelerate in the set deceleration time. When the DC bus voltage exceeds the Stall
Prevention level, the drive pauses deceleration. Deceleration continues as soon as 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.
Drive Input Voltage
200 V Class
400 V Class
Note: 1. This setting should not be used in combination with a Dynamic Braking Resistor or other braking options. If Stall Prevention during
deceleration is enabled, it will be triggered before the braking resistor option can operate.
2. This method may lengthen the total deceleration time compared to the set value. If this is not appropriate for the application consider
using a braking option.
Figure 5.84 illustrates the function of Stall Prevention during deceleration.
Setting 2: Intelligent Stall Prevention
With this setting the drive adjusts the deceleration rate so that the DC bus voltage is kept at the level set in parameter
L3-17. This way the shortest possible deceleration time is achieved while the motor is protected from stalling. The
deceleration time that has been selected is disregarded, but the achievable deceleration time can not 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
Refer to these parameter descriptions for details.
Note: As the deceleration time is not constant, Intelligent Stall Prevention should not be used in applications where stopping accuracy is a
concern. Use braking options instead.
Setting 3: Stall Prevention with Braking Option
Enables the Stall Prevention function while using a braking resistor. Use this setting if overvoltage occurs with L3-04
disabled when using a braking resistor. This makes it possible to reduce the deceleration time.
YASKAWA ELECTRIC SIEP C710606 16C YASKAWA AC Drive – V1000 Technical Manual
Name
E1-01 ≥ 400 V
E1-01 < 400 V
Output Frequency
specified deceleration time
Figure 5.84 Stall Prevention During Deceleration
5.8 L: Protection Functions
Setting Range
<1> <2>
0 to 4; 7
Stall Prevention Level during Deceleration
Vdc = 380 V
Vdc = 760 V
Vdc = 660 V
Deceleration characteristics
when Stall Prevention was
triggered during deceleration
Time
Default
1
5
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