B3: Speed Search - YASKAWA GA700 Technical Manual

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b3: Speed Search

The Speed Search function detects the actual speed of a coasting motor, then restarts the motor before the motor
stops. Use Speed Search in these conditions:
• To continue operation after momentary power loss
• To switch from commercial power supply to drive power
• To restart a coasting fan
For example, the drive output turns off and the motor coasts when there is a momentary loss of power. After you
return power, the drive does Speed Search on the coasting motor, and restarts the motor from the detected speed.
When you use a PM motor, enable b3-01 [Speed Search at Start Selection].
There are two types of Speed Search for induction motors: Current Detection and Speed Estimation. Use
parameter b3-24 [Speed Search Method Selection] to select the type of Speed Search.
Parameter settings are different for different types of Speed Search. Refer to
Parameter
b3-01 [Speed Search at Start Selection]
b3-03 [Speed Search Deceleration Time]
b3-05 [Speed Search Delay Time]
b3-06 [Speed Estimation Current Level 1]
b3-07 [Speed Estimation Current Level 2]
b3-08 [Speed Estimation ACR P Gain]
b3-09 [Speed Estimation ACR I Time]
b3-10 [Speed Estimation Detection Gain]
b3-14 [Bi-directional Speed Search]
b3-17 [Speed Est Retry Current Level]
b3-18 [Speed Est Retry Detection Time]
b3-19 [Speed Search Restart Attempts]
b3-24 [Speed Search Method Selection]
b3-25 [Speed Search Wait Time]
b3-26 [Direction Determination Level]
b3-27 [Speed Search RUN/BB Priority]
b3-29 [Speed Search Back-EMF Threshold]
b3-31 [Spd Search Current Reference Lvl]
b3-32 [Spd Search Current Complete Lvl]
b3-33 [Speed Search during Uv Selection]
b3-35 [Low Back EMF Detection Level]
b3-36 [High Back EMF Detection Level]
b3-54 [Search Time]
b3-55 [Current Increment Time]
Note:
• To use Speed Estimation Speed Search with V/f Control, do Rotational Auto-Tuning before you set the Speed Search function. If the
wire length between the drive and motor changed since the last time you did Auto-Tuning, do Stationary Auto-Tuning for Line-to-Line
Resistance process again.
• If A1-02 = 5, 6 [PM Open Loop Vector, PM Advanced Open Loop Vector] and the wiring distance between the motor and drive is long
or if the motor is coasting at more than or equal to 200 Hz, do not use Speed Search to restart the motor. Use Short Circuit Braking.
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Current Detection 2
Use this Speed Search function with induction motors. Set b3-24 = 2 [Speed Search Method Selection = Current
Detection 2]. Current Detection Speed Search injects current into the motor to detect the speed of an induction
YASKAWA ELECTRIC SIEP C710617 05F YASKAWA AC Drive GA700 Technical Manual
Table 11.26 Speed Search and Related Parameters
Current Detection 2
x
x
x
-
-
-
-
-
-
x
x
x
x (2)
x
-
x
-
x
x
x
x
x
-
-
11.3 b: Application
Table 11.26 for more information.
Speed Estimation
x
-
x
x
x
x
x
x
x
x
x
x
x (1)
x
x
x
-
-
-
x
x
x
-
-
11
713