YASKAWA CR700 Technical Manual page 773

• Overexcitation deceleration can be used with OLV control and CLV control, but cannot provide as significant
effect as V/f Control because it needs to secure torque accuracy.
• The following functions are disabled during braking using Overexcitation Deceleration 2, depending on the
control mode combined.
– Hunting Prevention Function (V/f Control Mode)
– Torque Limit Speed Control (Open Loop Vector Control Mode)
n3-13: OverexcitationBraking (OEB) Gain
■
No.
Name
(Hex.)
n3-13 OverexcitationBraking
(OEB) Gain
(0531)
The V/f pattern output value goes back to its usual level after the motor stops or accelerates again to the frequency
reference speed.
The best value of this parameter changes when the flux saturation characteristics of the motor change.
• Gradually increase the value of n3-13 to 1.25 or 1.30 to increase the braking power of Overexcitation
Deceleration. If the gain is too much, the motor can have flux saturation and cause a large quantity of current to
flow.
• This can increase the deceleration time. Decrease the setting value if flux saturation causes overcurrent. If you
increase the setting value, the drive can detect oC [Overcurrent], oL1 [Motor Overload], and oL2 [Drive
Overload]. Decrease the value of n3-21 [HSB Current Suppression Level] to prevent oC and oL.
• If you use overexcitation deceleration frequently or if you use overexcitation deceleration for an extended
period of time, it can increase motor temperature. Decrease the setting value in these conditions.
• If ov [Overvoltage] occurs, increase the deceleration time.
n3-14: OEB High Frequency Injection
■
No.
Name
(Hex.)
n3-14 OEB High Frequency
Injection
(0532)
Expert
Enable this parameter to set a shorter deceleration time.
Note:
• If you frequently use overexcitation deceleration on a motor, the motor loss will increase the risk of burn damage.
• When you set this parameter to 1, the motor can make a loud excitation sound during overexcitation deceleration. If the excitation
sound is unwanted, set this parameter to 0 to disable the function.
0 : Disabled
1 : Enabled
The drive injects harmonic signals at the time of overexcitation deceleration. You can decrease the deceleration
time because motor loss increases.
n3-21: HSB Current Suppression Level
■
No.
Name
(Hex.)
n3-21 HSB Current Suppression
Level
(0579)
If flux saturation during Overexcitation Deceleration makes the motor current become more than the value set in
n3-21, the drive will automatically decrease the overexcitation gain. If oC [Overcurrent], oL1 [Motor Overload],
or oL2 [Drive Overload] occur during overexcitation deceleration, decrease the setting value.
If repetitive or long overexcitation deceleration cause the motor to overheat, decrease the setting value.
YASKAWA SIEPC71061723A YASKAWA AC Drive CR700 Technical Manual
V/f CL-V/f OLV CLV AOLV
Sets the gain value that the drive multiplies by the V/f pattern output value during overexcitation
deceleration to calculate the overexcitation level.
V/f CL-V/f OLV CLV AOLV
Sets the function that injects harmonic signals during overexcitation deceleration.
V/f CL-V/f OLV CLV AOLV
Sets the upper limit of the current that is suppressed at the time of overexcitation deceleration as a
percentage of the drive rated current.
11.10 n: Special Adjustment
Description
Description
Description
Default
(Range)
1.10
(1.00 - 1.40)
Default
(Range)
0
(0, 1)
Default
(Range)
100%
(0 - 150%)
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