Mitsubishi Electric FR-A820-00046 Instruction Manual page 849

Parameters
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").
Pr. 802
(Pr. 1299)
setting
0
(initial value)
1
Tab. 5-306: Selection of pre-excitation
● The relation between the DC injection brake operation and pre-excitation operation is as follows.
Control method
V/F control
Advanced magnetic flux
vector control
Real sensorless vector
control
Vector control
PM sensorless vector
control,
low-speed range high-
torque mode disabled
PM sensorless vector
control,
low-speed range high-
torque mode enabled
Tab. 5-307: The relation between the DC injection brake operation and pre-excitation
FR-A800
Pre-
Description
excitation
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
Zero speed
external force.
control
It will not perform position control, but operate only with the speed control.
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.
Servo lock
To perform the position control, this loop gain can be adjusted with Pr. 422 "Position
control gain" (Pr. 1298 "Second position control gain").
Control Pr. 802
mode (Pr. 1299)
⎯ ⎯
⎯ ⎯
⎯
⎯
Speed
⎯
⎯
⎯
Torque
⎯
0
Speed
1
⎯
Torque
⎯
Position
⎯
Speed
0
Speed
1
⎯
Position
Pr. 850 Deceleration stop
⎯
DC injection brake
⎯
DC injection brake
0 DC injection brake
1 Zero speed
Magnetic flux decay
2
output shutoff
0 DC injection brake
1 Zero speed
Magnetic flux decay
2
output shutoff
⎯
Zero speed
⎯
Servo lock
⎯
Zero speed
⎯ ⎯
⎯
DC injection brake
⎯
Zero speed
⎯
Servo lock
⎯ ⎯
(G) Control parameters
X13-ON
LX-ON
(Pr. 11 = "8888")
⎯
DC injection brake
⎯
DC injection brake
Zero speed Zero speed
Zero speed Zero speed
Zero speed Zero speed
Zero speed Zero speed
Zero speed Zero speed
Servo lock Servo lock
Zero speed Zero speed
⎯
Servo lock
⎯ ⎯
⎯
Zero speed
⎯
Servo lock
⎯
Servo lock
5 - 669