YASKAWA V1000 Technical Manual page 215

• 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: 1. The motor speed will exceed the frequency reference when overvoltage suppression is triggered. Consequently, overvoltage
suppression is not appropriate in applications that require a perfect match between the frequency reference and the actual motor
speed.
2. Disable overvoltage suppression when using a braking resistor.
3. Overvoltage may still occur if there is a sudden increase to a regenerative load.
4. This function is enabled only when operating just below the maximum frequency. Overvoltage suppression does not increase the
output frequency beyond the maximum frequency. If this is required by the application increase the maximum frequency and change
the base frequency setting.
n L3-11: Overvoltage Suppression Function Selection
Enables or disables the overvoltage suppression function.
No.
L3-11
Setting 0: Disabled
The output frequency is not adjusted. A regenerative load may trip the drive with an overvoltage fault. Use this setting if
braking options are installed.
Setting 1: Enabled
When the DC bus voltage rises due to regenerative load, an overvoltage fault is prevented by increasing the output
frequency.
n L3-17: Target DC Bus Voltage for Overvoltage Suppression and Stall Prevention
Sets the target DC bus voltage target level used by the overvoltage suppression function (L3-11 = 1) and Intelligent Stall
Prevention during deceleration (L3-04 = 2).
No.
Target DC Bus Voltage for Overvoltage Suppression, and
L3-17
Intelligent Stall Prevention During Deceleration
<1> Values are for 200 V class drives and must be doubled for 400 V class drives.
<2> This value is initialized when E1-01 is changed.
n L3-20: DC Bus Voltage Adjustment Gain
Determines the proportional gain used by overvoltage suppression (L3-11 = 1), Kinetic Energy Backup 2, and Intelligent
Stall Prevention during deceleration (L3-04 = 2) in order to control the DC bus voltage.
No.
L3-20
Adjustment for KEB 2 and Intelligent Stall Prevention During Deceleration
• Increase this setting slowly in steps of 0.1 if overvoltage (ov) or undervoltage (Uv1) occurs at the beginning of
deceleration while KEB Ride-Thru 2 is enabled or Intelligent Stall Prevention during deceleration is activated.
• If this setting is too high, then a fair amount of speed or torque ripple can result.
Adjustment for Overvoltage Suppression
• Increase this setting slowly in steps of 0.1 if overvoltage suppression is enabled (L3-11 = 1) and a sudden increase in a
regenerative load results in an overvoltage (ov) fault.
• If this setting is too high, excessive speed or torque ripple can result.
n L3-21: Accel/Decel Rate Calculation Gain
Determines the proportional gain used by overvoltage suppression (L3-11 = 1), Kinetic Energy Backup 2, and Intelligent
Stall Prevention during deceleration (L3-04 = 2) in order to calculate acceleration and deceleration rates.
No.
L3-21
<1> This value is reset to its default value when the control mode is changed (A1-02). The value shown here is for Open Loop Vector Control.
Adjustment for KEB 2 and Intelligent Stall Prevention During Deceleration
• Reduce the setting in steps of 0.05 if there is a fairly large speed or current ripple during KEB Ride-Thru 2 or when
using Intelligent Stall Prevention during deceleration.
YASKAWA ELECTRIC SIEP C710606 16C YASKAWA AC Drive – V1000 Technical Manual
Name
ov Suppression Function Selection
Name
Name
DC Bus Voltage Adjustment Gain
Name
Accel/Decel Rate Calculation Gain
5.8 L: Protection Functions
Setting Range
0 or 1
Setting Range
<1>
150 to 400 370 V
Setting Range
0.00 to 5.00
Setting Range
0.00 to 200.00
Default
0
Default
<1> <2>
Default
1.00
5
Default
<1>
1.00
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