E6581090

4) Adjusting the PI control gain level

Adjust the PI control gain level according to the process quantity, the feedback signal and the object to be controlled.

The following parameters are provided for gain adjustment.

Parameter

Adjustment range

Default setting

H (P gain)

0.01100.0

0.30

H (I gain)

0.01100.0

0.20

H (Proportional (P) gain adjustment parameter)

This parameter is used to adjust the proportional gain level during PI control. A correction factor, which is proportional to the particular deviation (the difference between the set frequency and the feedback value), is obtained by multiplying this deviation by the parameter setting.

Increasing the P gain increases response. However, increasing it higher than required results in an undesirable event such as hunting.

6

Fast response

Process quantity

 

setting

 

 

Slow response

Time

H (Integral (I) gain adjustment parameter)

This parameter is used to adjust the integral gain level during PI control. Any deviations remaining after proportional control are cleared to zero (residual deviation offset function).

Increasing the I gain increases response. However, increasing it higher than required results in an undesirable event such as hunting.

Process quantity setting

Residual deviation

Time

5) Adjusting an analog command voltage

To use feedback input (VI/S3 terminal), perform a voltage-scaling adjustment as required. See Section 6.4.1 for details.

If the feedback input value is very small, the voltage-scaling adjustment value can also be used for gain adjustment.

Example of voltage signal setting

Example of current signal setting

H

 

H

 

 

(80Hz)

 

(80Hz)

 

 

 

 

 

H

 

H

 

(0Hz) 0V

 

 

10V

(0Hz) 4mA

20mA

H

H

H

H

0%

100%

20%

100%

 

 

 

 

 

 

F-18

 

Page 82
Image 82
Toshiba VF-nC1 instruction manual Adjusting the PI control gain level, Adjusting an analog command voltage