Yaskawa G7 Drive - Manual (Page 325)

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„ Adjusting Energy-saving Control
The method of adjustment during energy-saving control operations differs depending on the control method.
Refer to the following when making adjustments.
V/f Control
In V/f control method, the voltage for optimum motor efficiency is calculated and becomes the output voltage
reference.
• b8-04 (Energy-saving Coefficient) is set at the factory for motor use applied to the Drive. If the motor
capacity differs from the motor applied to the Drive, set the motor capacity in E2-11 (Motor Rated Output).
Also, adjust the output voltage in steps of 5 until it reaches minimum. The larger the energy-saving coeffi-
cient, the greater the output voltage.
• To improve response when the load fluctuates, reduce the power detection filter time constant b8-05. If b8-
05 is set too small, however, motor rotations when the load is light may become unstable.
• Motor efficiency varies due to temperature fluctuations and differences in motor characteristics. Conse-
quently, control motor efficiency online to optimize efficiency by causing minute variations in voltage
using the search operation. Parameter b8-06 (Search Operation Voltage Limiter) controls the range that
control the voltage using the search operation. For 200-240V Class Drives, set the range to 100%/200 V,
and for 380-480V Class Drives, set the range to 100%/380-480 V. Set to 0 to disable the search operation.
Vector Control
In vector control method, control the slip frequency so that motor efficiency is maximized.
• Taking the motor rated slip for the base frequency as optimum slip, calculate the optimum slip for motor
efficiency for each frequency. In vector control, be sure to perform autotuning, and set the motor rated slip.
• If the motor performs hunting when using energy-saving control in vector control, reduce the set value in
b8-02 (Energy-saving Gain), or increase the set value in b8-03 (Energy-saving Filter Time Constant).
‹ Setting Motor Parameters
In vector control method, the motor parameters are set automatically using autotuning. If autotuning does not
complete normally, set them manually.
„ Related Parameters
Parameter
Number
Name
Description
Setting
Range Factory
Setting
Change
during
Operation
Control Methods
Display V/f
V/f
with
PG
Open
Loop
Vector
1
Flux
Vector
Open
Loop
Vector
2
E2-01
Motor Rated
Current Sets the motor nameplate full load
current in amperes (A). This value
is automatically set during
Auto-Tuning. 0.32
to
6.40
*2
1.90 A
*1
No Q Q Q Q Q
Motor Rated
FLA
E2-02
Motor Rated
Slip Sets the motor rated slip in hertz
(Hz). This value is automatically
set during rotational
Auto-Tuning.
0.00
to
20.00
2.90Hz
*1
No A A A A A
Motor Rated
Slip