YASKAWA GA700 Technical Manual page 844

11.9 L: Protection Function
Set the following parameters as necessary when using the overvoltage suppression function.
• L3-20 [DC Bus Voltage Adjustment Gain]
• L3-21 [Accel/Decel Rate Calculate Gain]
• L3-24 [Motor Accel Time for Inertia Cal]
• L3-25 [Load Inertia Ratio]
Note:
• The motor speed will exceed the frequency reference when overvoltage suppression is triggered. Do not use overvoltage suppression
for applications that require a perfect match between the frequency reference and the motor speed.
• Set L3-11 = 0 [Disabled] when using a braking resistor.
• The overvoltage suppression function is enabled only when operating just below the maximum frequency. Overvoltage suppression
does not increase the output frequency beyond the maximum frequency. After confirming the motor and machine specifications as
necessary depending on the application, increase the maximum frequency.
• ov may still occur if there is a sudden increase to a regenerative load.
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L3-01: Stall Prevent Select during Accel
No.
Name
(Hex.)
L3-01 Stall Prevent Select
duringAccel
(048F)
Note:
The setting range is between 0 and 1 when A1-02 = 5 [Control Method Selection = PM Open Loop Vector Control].
Stall prevention during acceleration prevents the stalling and stopping of motors when oC [Overcurrent], oL2
[Drive Overloaded], or oL1 [Motor Overload] is detected in cases of significant loads applied during acceleration
or sudden acceleration times regarding load inertia are set.
0 : Disabled
The Stall Prevention function does not operate during acceleration, and acceleration occurs for the set acceleration
time. If the acceleration time is too short, the motor does completely accelerate during the set time, which causes
oL1 or oL2 to be detected and the motor to stop.
1 : Enabled
The Stall Prevention During Acceleration function is enabled. Operation varies depending on the selected control
mode.
• V/f Control Mode, Open Loop Vector Control, or EZ Open Loop Vector Control
The drive stops acceleration once the output current exceeds the value set in L3-02 [Stall Prevent Level during
Accel]. The drive starts acceleration again once the output current falls below the value set in L3-02 - 15%. The
Stall Prevention function level automatically falls for constant output ranges.
Figure 11.127 Stall Prevention During Acceleration when Using Induction Motors
• Open Loop Vector Control for PM
844
V/f CL-V/f OLV CLV AOLV
Selects the method of the Stall Prevention During Acceleration function.
YASKAWA ELECTRIC SIEP C710617 01B YASKAWA AC Drive GA700 Technical Manual
Description
OLV/PM AOLV/PM CLV/PM EZOLV OLV/PM
Default
(Range)
1
(0 to 3)