Setting 2: Intelligent Stall Prevention
The drive adjusts the deceleration rate so the DC bus voltage is kept at the level set to parameter L3-17
<1>
. This produces the
shortest possible deceleration time while protecting the motor from stalling. The selected deceleration time is disregarded and
the achievable deceleration time cannot be smaller than 1/10 of the set deceleration time.
This function uses the following parameters for adjusting the deceleration rate:
• DC bus voltage gain (L3-20
<1>
)
• Deceleration rate calculations gain (L3-21
<1>
)
• Inertia calculations for motor acceleration time (L3-24
<1>
)
• Load inertia ratio (L3-25)
<1> Details on this function can be found in the standard Z1000 Programming Manual (SIEPC71061645) at
www.yaskawa.com.
Note:
The deceleration time is not constant. Do not use Intelligent Stall Prevention in applications where stopping accuracy is a concern.
Setting 4: Overexcitation Deceleration 1
Overexcitation Deceleration 1 (increasing the motor flux) is faster than deceleration with no Stall Prevention (L3-04 = 0).
Setting 4 changes the selected decel time and functions to provide protection from an overvoltage trip.
Setting 5: Overexcitation Deceleration 2
Overexcitation Deceleration 2 slows down the motor while trying to maintain the DC bus voltage at the level set to parameter
L3-17
<1>
. This function shortens the achievable deceleration time more than by using Overexcitation Deceleration 1. Setting
5 will shorten/lengthen the decel time to maintain the L3-17
<1>
bus level.
<1> Details on this function can be found in the standard Z1000 Programming Manual (SIEPC71061645) at
www.yaskawa.com.
n
L3-06: Stall Prevention Level during Run
Sets the current level to trigger 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).
The Stall Prevention level can be adjusted using an analog input.
Refer to Multi-Function Analog Input Terminal Settings
for details.
No.
Name
Setting Range
Default
L3-06
Stall Prevention Level During Run
n
L3-11: Overvoltage Suppression Function Selection
Enables or disables the overvoltage suppression function.
No.
Name
Setting Range
Default
L3-11
Overvoltage Suppression Function Selection
0, 1
0
Setting 0: Disabled
The regenerative torque limit and the output frequency are not adjusted. A regenerative load may trip the drive with an
overvoltage fault. Use this setting if dynamic braking options are installed.
Setting 1: Enabled
When the DC bus voltage rises due to regenerative load, an overvoltage fault is prevented by decreasing the regenerative
torque limit and increasing the output frequency.
5.9 L: Protection Functions
172
YASKAWA ELECTRIC SIEP YAIZ1B 01E YASKAWA AC Drive – Z1000 Bypass Technical Manual
