YASKAWA GA700 - Features and Advantages of Control Methods

1.3 Features and Advantages of Control Methods
26 YASKAWA ELECTRIC SIEP C710617 05F YASKAWA AC Drive GA700 Technical Manual
1.3 Features and Advantages of Control Methods
This drive has 9 available control methods from which to select for different applications. Table 1.5, Table 1.6 and
Table 1.7 gives information about the features of each control method.
Table 1.5 V/f and CL-V/f Features and Advantages of Control Methods
Control Method
Selection
Open Loop V/f Control
(V/f)
Closed Loop V/f Control
(CL-V/f)
Notes
Controlled Motor Induction Motor -
Parameter Settings A1-02 = 0 A1-02 = 1 -
Basic Control V/f
Closed loop V/f control with
speed correction
-
Main Applications
General-purpose variable speed
control to connect more than one
motor to one drive.
High-precision speed control with
encoders on machines
-
PG Option Card Not necessary Necessary (PG-B3 or PG-X3) -
Maximum Output
Frequency
590 Hz 400 Hz -
Speed Control Range 1:40 1:40
This is the range of variable control.
When you connect and operate motors in
this method, think about the increase in
motor temperature.
Starting Torque 150% / 3 Hz 150% / 3 Hz
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.
Auto-Tuning
*1
Rotational and Line-to-Line
Resistance (usually not necessary)
Rotational and Line-to-Line
Resistance (usually not necessary)
Automatically tunes electrical motor
parameters.
Torque Limits
*1
No No
Controls maximum motor torque to
prevent damage to machines and loads.
Torque Control
*1
No No
Directly controls motor torque to control
tension and other parameters.
Droop Control
*1
No No
Sets load torque slip for motors.
Distributes motor loads.
Zero Servo Control
*1
No No
Locks servos without an external position
controller to prevent movement caused by
external force.
Speed Search
*1
Yes -
Immediately estimates (or detects) motor
speed and direction when coasting to a
stop to quickly start-up the drive without
stopping the motor.
Automatic Energy-
saving Control
*1
Yes Yes
Automatically adjusts the voltage applied
to motors to maximize motor efficiency
for all load sizes.
High Slip Braking
(HSB)
*1
Yes Yes
Increases motor loss to let the motor
decelerate faster than usual without a
braking resistor. Motor characteristics
have an effect on this function.
Feed Forward Control
*1
No No
Compensates effects of the system inertia
to increase the speed precision when the
load changes.
KEB Ride-Thru
Function
*1
Yes Yes
Quickly and safely stops the motor during
power loss and automatically starts
operation at the previous speed when
restores power without coasting the motor.