YASKAWA V1000 Series

• Momentary power loss is shorter than the minimum baseblock time (L2-03):
AC power
supply
output
frequency
output
current
OFFON
starts at the speed
that was detected
selected
frequency
reference
min baseblock time
(L2-03)
several miliseconds
*2
*1
Figure 5.10 Duration of Power Loss < L2-03: Speed Search after Baseblock
*1. Baseblock time may be shortened on account of the output frequency prior to baseblock.
*2. Once AC power is restored, the drive will wait for at least the time set to b3-05.
• Momentary power loss is longer than the minimum baseblock time (L2-03):
AC power
supply
output
frequency
output
current
OFFON
starts at the frequency
that was detected
selected
frequency
reference
minimum baseblock time
(L2-03)
several miliseconds
Speed Search wait time
(b3-05)
Figure 5.11 Duration of Power Loss > L2-03: Speed Estimation after Baseblock
Note: Speed Search will sometimes operate as shown in the first diagram if the frequency is relatively low just before baseblock or if the duration of power loss is relatively long.
Current Detection Speed Search (b3-24 = 0)
Searches for the motor speed from the maximum frequency and by using the frequency when momentary power loss occurred. Detects speed with the
motor current level. Current Detection Speed Search works only in one direction. To enable Current Detection Speed Search, set b3-24 to 0 and b3-01 to
1.
Set the multi-function inputs for “External Speed Search Command 1” or “External Speed Search Command 2” (H1-฀฀ = 61 or 62). External Speed
Search Command 1 looks for the motor speed from the maximum frequency set to E1-04. External Speed Search Command 2 looks for the motor speed
by starting from the set frequency and decelerating until the speed of the rotor and the output frequency match.
Note: Increase the voltage recovery ramp time set to L2-04 if a UV1 fault occurs when performing Current Detection Speed Search. Shorten the Speed Search deceleration time set
to b3-03 if an OL1 fault occurs while performing Current Detection Speed Search. Increase the minimum baseblock time set to L2-03 if an overcurrent fault occurs when
performing Speed Search after power is restored following a momentary power loss. Current Detection Speed Search is not available when using PM Open Loop Vector
Control.
The timechart below demonstrates how Speed Serach at start and an external Speed Search command operate.
run command
output
frequency
output current
OFF ON
b3-02
decel time set
set to b3-03
waits for twice
as long as L2-04
selected
frequency
reference
minimum baseblock time*
(L2-03)
max output frequency
or the specified
frequency reference
*
Lower limit is the the Speed
Search wait time set to b3-05.
Figure 5.12 Current Detection Speed Search at Start
5.2 b: Setup
YASKAWA ELECTRIC SIEP C710606 18A YASKAWA AC Drive – V1000 Technical Manual (Preliminary)
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Parameter Details