Yaskawa Matrix Converter - Manual (Page 224)

Continuing Operation
6-
59
‹ Speed Search
The speed search function finds the actual speed of the motor that is rotating using inertia, and then starts
smoothly from that speed. When restoring power after a temporary power loss, the speed search function
switches connection from the commercial power supply, and then restarts the fan that is rotating using inertia.
„ Related Parameters
Parameter
Number
Name
Description
Setting
Range
Default
Change
during
Run
Control Methods
Display V/f
Open
Loop
Vector
Flux
Vector
b3-01
Speed Search
Selection Enables/disables the speed search function for
the Run Command and sets the speed search
method.
0: Disabled, speed calculation
1: Enabled, speed calculation
2: Disabled, current detection
3: Enabled, current detection
Speed Calculation:
When the search is started, the motor speed is
calculated and acceleration/deceleration is
performed from the calculated speed to the
specified frequency (motor direction is also
searched).
Current Detection:
The speed search is started from the fre-
quency when power was momentarily lost
and the maximum frequency, and the speed is
detected at the search current level.
0 to 3 *1 0 No A A No
SpdSrch at Start
b3-02
Speed Search
Deactivation Cur-
rent Used only when b3-01 = 2 or 3. Sets speed
search operating current in units of percent,
with MxC rated current as 100%.
Note: Normally not necessary to change. If
the MxC won’t run after a restart, lower
this value.
0 to
200
100% *2 No A A No
SpdSrch Current
b3-03
Speed Search
Deceleration Time Used only when b3-01 = 2 or 3. Sets the
deceleration time during speed search.
0.1 to
10.0
2.0 s No A A No
SpdSrch Dec Time
b3-04
*4
Current Suppres-
sion Gain During
Search
Sets the gain used to suppress output current
during a current detection speed search.
If resistor overheat (SOH) occurs, reduce the
setting.
10 to
100
100%
*3
No A A No
SpdSrch I Gain
b3-05
Speed Search
Delay Time
Delays the speed search operation after a
momentary power loss to allow time for an
external output contactor to re-energize.
0.0 to
20.0
0.2 s No A A A
Search Delay
b3-10
Speed Search
Detection Com-
pensation Gain
Sets the gain for the frequency at which the
MxC starts speed estimation speed search.
Use only when b3-01 = 0 or 1.
1.00 to
1.20
1.15 No A A No
Srch Detect Comp
b3-14
Bi-directional
Speed Search
Selection This parameter enables the MxC to detect the
direction of rotation of the motor during speed
search.
0: Disable - MxC uses frequency reference
direction.
1: Enable - MxC uses detected direction
0 or 1 0 No A A No
Bidir Search Sel