Veichi JT550 Series Manual page 98

Chapter 7 Maintenance and Troubleshooting
To improve the system response, increase the proportional gain or reduce the integral time. Remember
to increase proportional gain first to ensure that the system does not oscillate, and then reduce integral time to
ensure that the system has quick response and small overshoot.
Note:Incorrect PI setting may cause large speed overshoots and a fast falling speed drop may cause an over
voltage on the DC bus.
F5.06 Vector control slip gain
This function improves control performance in SVC/FVC (F0-01 = 0/1).
For FVC (F0-01 = 1), it can adjust output current of the AC drive. Decrease this parameter gradually when a
large rating AC drive is controlling a lightly loaded motor. Adjustment of this parameter is not required
normally.
Time constant of speed loop
F5.07
This parameter takes effect only when F0-01 = 0. You can improve motor stability by increasing F5.07.
Be aware that this may slow dynamic response. Decreasing it will obtain quick system response but may lead
to motor oscillation. Adjustment of this parameter is not required normally.
F5.08 Vector control over excitation gain
During deceleration, over-excitation control can restrain rise of the bus voltage to avoid the
over-voltage fault. The larger the over-excitation gain is, the better the restraining effect is.
Increase the over-excitation gain if the inverter is liable to over-voltage error during deceleration. Too
large over-excitation gain, however, may lead to an increase in output current. Therefore, set this parameter to
a proper value in actual applications.
Set the over-excitation gain to 0 in applications of small inertia (the bus voltage will not rise during
deceleration) or where there is a braking resistor.
Torque upper limit source in speed
F5.09
Digital setting of torque upper limit
F5.10
in speed control mode
0: Set by F5.10
1: AI1
2: AI2
3: AI3
4: Pulse setting (X5)
5: Via communication
6: MIN(AI1,AI2)
7: MAX(AI1,AI2)
When the inverter is in communication with the master, if F5.09 is set to 5 "communication setting",
F5.10"Digital setting of torque upper limit in speed control mode" can be set via communication from the
master.
In other conditions, the host computer writes data -100.00% to 100.00% by the communication address
0x1000, where 100.0% corresponds to the value of F5.10.
filter
control mode
Range:50%~200%
Range:0.000s~0.100s
Range:0~200
Range:0~7
Range:0.0%~200.0%
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JT550 Series Inverter Manual
Default:100%
Default:0.000s
Default:64
Default:0
Default:150.0%