YASKAWA A1000 Technical Manual page 279


Parameters for KEB Ride-Thru
Table 5.42 lists parameters needed to set up KEB Ride-Thru depending the type of KEB Ride-Thru selected in L2-29.
Parameter Name
C1-09 Fast Stop Time
C2-03 S-Curve at Deceleration Start
L2-05 Undervoltage Detection Level
L2-06 KEB Deceleration Time
L2-07 KEB Acceleration Time
L2-08 Frequency Gain at KEB Start
L2-10 KEB Detection Time
Desired DC Bus Voltage
L2-11
during KEB
L3-20 Main Circuit Adjustment Gain
Accel/Decel Rate
L3-21
Calculation Gain
L3-24 Motor Acceleration Time
L3-25 Load Inertia Ratio

L2-02: Momentary Power Loss Ride-Thru Time
Sets the maximum time allowed to ride through a power loss. If power loss operation exceeds this time, the drive will
attempt to accelerate back to frequency reference. This parameter is valid if L2-01 = 1 or 3.
Note: The amount of time the drive is capable of recovering after a power loss is determined by the capacity of the drive. Drive
capacity determines the upper limit for L2-02.
No.
L2-02

L2-03: Momentary Power Loss Minimum Baseblock Time
Sets the minimum baseblock time when power is restored following a momentary power loss. This determines the time
the drive waits for the residual voltage in the motor to dissipate. Increase this setting if overcurrent or overvoltage occurs
at the beginning of Speed Search, after a power loss, or during DC Injection Braking.
No.
L2-03

L2-04: Momentary Power Loss Voltage Recovery Ramp Time
Sets the time for the drive to restore the output voltage to the level specified by the V/f pattern after Speed Search. The
setting value determines the time for the voltage to go from 0 V to the maximum voltage.
No.
L2-04
YASKAWA ELECTRIC SIEP C710616 27G YASKAWA AC Drive A1000 Technical Manual
Table 5.42 KEB Function Related Adjustments
• Increase if an overvoltage fault (ov) occur during KEB deceleration.
• Decrease if an undervoltage fault (Uv1) occurs during KEB deceleration.
• Shorten if undervoltage (Uv1) occurs right after KEB Ride-Thru is triggered.
• Lengthen this setting if overvoltage occurs right after KEB operation starts.
Increase if an undervoltage fault (Uv1) fault occurs at KEB operation start in order to let the drive
detect power loss more quickly.
• Increase if an overvoltage fault (ov) occur during KEB deceleration
• Decrease if an undervoltage fault (Uv1) occurs during KEB deceleration
Adjust to the desired acceleration time. If set to 0, standard acceleration times are used (C1-01,
C1-03, C1-05, C1-07).
• Increase if an undervoltage fault occurs right after KEB operation starts.
• Decrease if an overvoltage fault occurs right after KEB operation starts.
• Increase when a digital input is set for KEB Ride-Thru and an undervoltage fault occurs after
power was lost because the device that controls the input does not react quickly enough.
• If the DC bus voltage overshoots after KEB Ride-Thru begins (and no input terminal is set to
KEB Ride-Thru), increase L2-10 to longer than the overshoot.
• Set to around 1.22 times the input voltage for Single Drive KEB Ride-Thru 2.
• Set to around 1.4 times the input voltage for Single Drive KEB Ride-Thru 1 and System KEB
Ride-Thru modes.
• Increase this setting slowly in steps of 0.1 if overvoltage (ov) or undervoltage (Uv1) occurs at the
beginning of deceleration
• Reduce if torque ripple occurs during deceleration while executing KEB Ride-Thru.
• Reduce L3-21 in steps of 0.05 if there is a fairly large speed or current ripple.
• Decreasing this setting too much can result in a slow DC bus voltage control response, and may
lead to problems with overvoltage or undervoltage.
Set the motor acceleration time as described on page 287.
Set the load/inertia ratio as described on page 287.
Name
Momentary Power Loss Ride-Thru Time
Name
Momentary Power Loss Minimum Baseblock Time
Name
Momentary Power Loss Voltage Recovery Ramp Time
Setting Instructions
Setting Range
0.0 to 25.5 s
Setting Range
0.1 to 5.0 s
Setting Range
0.0 to 5.0 s
5.8 L: Protection Functions
KEB Mode (L2-29)
0 1 2
YES NO NO
YES NO YES
YES YES YES
NO NO YES
YES YES YES
YES NO YES
YES YES YES
YES YES YES
NO YES NO
NO YES NO
NO YES NO
NO YES NO
Default
Determined by C6-01 and
o2-04
Default
Determined by C6-01
and o2-04
Default
Determined by C6-01 and
o2-04
3
NO
YES
YES
YES
YES
YES
YES
YES
NO
NO
NO
NO
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