YASKAWA GA700 Technical Manual page 27

Open Loop V/f Control
Control Method
Selection
Controlled Motor
Overexcitation
Yes
Deceleration
*1
Overvoltage
Yes
Suppression Function
*1 *2
*1 Note these points when you use this function:
• When you can decouple the motor and machine for a test run, use Rotational Auto-Tuning. You must make adjustments to the
control in the range where there is no vibration in the machine after Rotational Auto-Tuning.
• Motor loss increases during overexcitation braking and high-slip braking. Use a maximum braking frequency of 5% ED and a
maximum braking time of 90 seconds. After you start high-slip braking, you cannot restart the motor until it stops. Use
overexcitation braking to decelerate over a shorter time at a pre-determined speed.
*2 Do not use this function with hoist application.
Table 1.6 OLV, CLV and AOLV Features and Advantages of Control Methods
Open Loop Vector
Control
Control
Method
Selection
(OLV)
Controlled
Motor
A1-02 = 2
Parameter
Settings
(Default)
Open Loop Current Vector
Basic Control
Control
• General-purpose
variable speed control
Main
• Applications in which
Applications
high performance is
necessary without
machine encoders
PG Option Card Not necessary
Maximum Output
590 Hz
Frequency
Speed Control
1:200
Range
Starting Torque 200% / 0.3 Hz
Rotational, Stationary, and
Auto-Tuning
*2
Line-to-Line Resistance
Torque Limits Yes
*2
Torque Control No
*2
Droop Control No
*2
YASKAWA ELECTRIC SIEP C710617 05F YASKAWA AC Drive GA700 Technical Manual
Closed Loop V/f Control
(V/f)
Induction Motor
Yes
Yes
Closed Loop Vector
Control
(CLV)
Induction Motor
A1-02 = 3
Closed Loop Current
Vector Control
Very high-performance
control with motor
encoders
Example: High-precision
speed control, torque
control, torque limits
Necessary (PG-B3 or PG-
X3)
400 Hz
1:1500
200% / 0 min -1
*1 *1
Rotational, Stationary, and
Line-to-Line Resistance
Yes
Yes
Yes
1.3 Features and Advantages of Control Methods
(CL-V/f)
Sets the V/f higher than the setting value
during deceleration to increase motor loss
and decrease deceleration time.
Adjusts speed during regeneration to
prevent overvoltage.
Advanced Open Loop
Vector Control
(AOLV)
A1-02 = 4
Open Loop Current Vector
Control
Sensorless vector control
with speed control
• General-purpose
variable speed control
• Applications in which
high performance is
necessary without
machine encoders
Not necessary
120 Hz
1:200
200% / 0.3 Hz
*1
Rotational, Stationary, and
Line-to-Line Resistance
Yes
Yes (Although NOT low
speeds of approximately
10% or less)
Yes
Notes
-
Notes
-
-
-
-
-
-
This is the range of variable
control.
When you connect and operate
motors in this mode, think about
the increase in motor
temperature.
This is the motor torque that the
drive can supply at low speed
during start-up and the related
output frequency (rotation
speed).
You must think about drive
capacity when a large quantity of
torque is necessary at low speed.
Automatically tunes electrical
motor parameters.
Controls maximum motor torque
to prevent damage to machines
and loads.
Directly controls motor torque to
control tension and other
parameters.
Sets load torque slip for motors.
Distributes motor loads.
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