YASKAWA V1000 Technical Manual page 214

5.8 L: Protection Functions
Setting 4: Overexcitation Deceleration
Enables overexcitation deceleration. Overexcitation Deceleration (increasing the motor flux) shortens the deceleration
time compared to deceleration with no Stall Prevention (L3-04 = 0). Repetitive or long overexcitation deceleration can
result in motor overheat. In such situations, either shorten the deceleration time setting or use a braking resistor option.
Use parameters n3-13 and n3-23 for fine-tuning this function.
Note: Because the allowable flux level for overexcitation varies based on the flux saturation characteristics of the motor, set the proper
overexcitation level by adjusting the excitation gain in parameter n3-13. Motor characteristics and inertia of the machine influence the
deceleration time during overexcitation deceleration.
Setting 7: Overexcitation Deceleration 3
Provides faster deceleration than normal Overexcitation Deceleration (L3-04 = 4) by increasing the amount of
overexcitation current applied to the motor.
Note: When operation permits, use normal Overexcitation Deceleration (L3-04 = 4).
n
L3-05: Stall Prevention Selection During Run
Stall Prevention During Run can prevent a motor from stalling by automatically reducing the speed when a transient
overload occurs while the motor is running at constant speed.
This parameter selects the Stall Prevention During Run method.
No.
L3-05
Note: 1. This function is not available in Open Loop Vector Control. Use the torque limit function instead.
2. When output frequency is 6 Hz or less, Stall Prevention During Run is disabled regardless of the setting in L3-05/06.
Setting 0: 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.
Setting 1: Decelerate Using C1-02
If the current exceeds the Stall Prevention level set in parameter L3-06, the drive decelerates at Decel Time 1 (C1-02).
Once the current level drops below the value of L3-06 minus 2% for 100 ms it accelerates back to the frequency reference
at the active acceleration time.
Setting 2: Decelerate Using C1-04
Same as setting 1 except the drive decelerates at decel time 2 (C1-04).
n L3-06: Stall Prevention Level During Run
Sets the current level for Stall Prevention During Run. Depending on the setting of parameter L3-23 the level is
automatically reduced in the constant power range (speed beyond base speed).
No.
L3-06
<1> The upper limit and default value for this setting are determined by C6-01, Drive Duty Selection, and L8-38, Carrier Frequency Reduction
Selection.
n
L3-23: Automatic Stall Prevention Level Reduction
This function reduces the Stall Prevention during run level in the constant power range.
No.
Automatic Reduction Function Selection for Stall Prevention
L3-23
Setting 0: Disabled
The level set in L3-06 is used throughout the entire speed range.
Setting 1: Enabled
The Stall Prevention level during run is reduced in the constant power range. The lower limit will be 40% of L3-06.
n Overvoltage Suppression Function
This function suppresses overvoltage faults by slightly increasing the output frequency when the DC bus voltage rises. It
can be used to drive loads with cyclic regenerative operation, such as punch presses or other applications that involve
repetitive crank movements.
The output frequency is adjusted during ov suppression so that the DC bus voltage does not exceed the level set in parameter
L3-17. In addition to the parameters explained below, ov suppression also uses these settings for frequency adjustment:
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Name
Stall Prevention Selection During Run
Name
Stall Prevention Level During Run
Name
during Run
YASKAWA ELECTRIC SIEP C710606 16C YASKAWA AC Drive – V1000 Technical Manual
Setting Range
0 to 2
Setting Range
<1>
30 to 150
Setting Range
0 or 1
Default
1
Default
<1>
Default
0