Mitsubishi Electric FR-A800, Instruction Manual

Page: 849 / 1042

Parameters (G) Control parameters
FR-A800 5 - 669
Braking operation selection for vector control, PM sensorless vector control (Pr. 802, Pr. 1299)
●
Select the braking operation when the pre-excitation is performed with Pr. 802 "Pre-excitation
selection" from either zero speed control or servo lock.
●
Turning ON the RT signal enables the second pre-excitation selection (when Pr. 450
≠
"9999").
●
The relation between the DC injection brake operation and pre-excitation operation is as follows.
Pr. 802
(Pr. 1299)
setting
Pre-
excitation
Description
0
(initial value)
Zero speed
control
It will try to maintain 0 r/min so the motor shaft will not rotate even when a load is
applied. However, it will not return to its original position when the shaft moves due to
external force.
It will not perform position control, but operate only with the speed control.
1 Servo lock
It will try to maintain the position of the motor shaft even if a load is applied. When the
shaft moves due to external force, it will return to its original position after the external
force is removed.
To perform the position control, this loop gain can be adjusted with Pr. 422 "Position
control gain" (Pr. 1298 "Second position control gain").
Tab. 5-306: Selection of pre-excitation
Control method
Control
mode Pr. 802
(Pr. 1299)
Pr. 850 Deceleration stop LX-ON
X13-ON
(Pr. 11 = "8888")
V/F control
⎯ ⎯ ⎯
DC injection brake
⎯
DC injection brake
Advanced magnetic flux
vector control
⎯ ⎯ ⎯
DC injection brake
⎯
DC injection brake
Real sensorless vector
control
Speed
⎯
0 DC injection brake
Zero speed Zero speed
⎯
1 Zero speed
⎯
2
Magnetic flux decay
output shutoff
Zero speed Zero speed
Torque
⎯
0 DC injection brake
Zero speed Zero speed
⎯
1 Zero speed
⎯
2
Magnetic flux decay
output shutoff
Zero speed Zero speed
Vector control
Speed
0
⎯
Zero speed Zero speed Zero speed
1
⎯
Servo lock Servo lock Servo lock
Torque
⎯ ⎯
Zero speed Zero speed Zero speed
Position
⎯ ⎯ ⎯
Servo lock
⎯
PM sensorless vector
control,
low-speed range high-
torque mode disabled
Speed
⎯ ⎯
DC injection brake
⎯ ⎯
PM sensorless vector
control,
low-speed range high-
torque mode enabled
Speed
0
⎯
Zero speed Zero speed
⎯
1
⎯
Servo lock Servo lock
⎯
Position
⎯ ⎯ ⎯
Servo lock
⎯
Tab. 5-307: The relation between the DC injection brake operation and pre-excitation