YASKAWA VARISPEED-616G5, Instruction Manual

Page: 205 / 355

7.5 Common Functions
7 - 51
J
PID Output Gain: b5-10 (for SPEC: F)
User
Change
during Setting Factory
Valid Access Levels
User
Constant
Number
Name
g
during
Opera-
tion
Setting
Range
Unit Factory
Setting
V/f
Control
V/f with
PG
Open
Loop
Vector
Flux
Vector
b5-10 PID output gain
×
0.0 to 25.0
Mul
tiple
1.0 A A A A
D
Constant b5-10 adjusts the PID control gain.
J
Reverse PID Output: b5-11 (for SPEC: F)
User
Change
during Setting Factory
Valid Access Levels
User
Constant
Number
Name
g
during
Opera-
tion
Setting
Range
Unit Factory
Setting
V/f
Control
V/f with
PG
Open
Loop
Vector
Flux
Vector
b5-11
Reverse PID output
selection
×
0, 1 − 0 A A A A
D
Settings
Setting Function
0 Executes 0 limit if PID output is negative (does not reverse).
1 Reverse rotation if PID output is negative.
D
The rotation will not reverse if reverse is prohibited by b1-04.
Adjusting PID Control
Use the following procedure to activate PID control and then adjust it while monitoring the response.
1. Enable PID control (set b5-01 to 2 or 1).
2. Increase the proportional gain P in b5-02 as far as possible without creating oscillation.
3. Reduce the integral time I in b5-03 as far as possible without creating oscillation.
4. Increase the differential time (D) in b5-05 as far as possible without creating oscillation.
Making Fine Adjustments
First set the individual PID control constants, and then make fine adjustments.
D
Reducing Overshooting
If overshooting occurs, shorten the derivative time (D) and lengthen the integral time (I).
After adjustment
Before adjustment
Response
Time
D
Rapidly Stabilizing Control Status
To rapidly stabilize the control conditions even when overshooting occurs, shorten the integral time
(I) and lengthen the derivative time (D).
Before adjustment
After adjustment
Response
Time
D
Reducing Long-cycle Oscillation
If oscillation occurs with a longer cycle than the integral time (I) setting, it means that integral opera-
tion is strong. The oscillation will be reduced as the integral time (I) is lengthened.
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