GE Industrial Solutions DV-300 DC Drive Users Manual - Manual (Page 287)

DV-300 Adjustable Speed Drives
——— FUNCTION DESCRIPTION ———
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To obtain the correct value it must be added the decimal number 8192 (fixed offset)
PID target = 8192 + 42 = 8234
Set PID out scale so that, along with the max. analog value on Analog input 2 (Feed-fwd PID = 8500) and
with Enable PI PID e Enable PD PID = disable, Speed ref 1 is the same at 2550rpm.
Speed ref 1 will be set in RPM x 4, so:
PID out scale = (2550 x 4) / 8500 = 1.2
Set PI central v sel = 1.
Set PI central v 1 = 1
In the absence of a correction carried out from the PI block of the regulator, the line speed reference (Feed-
forward) must be multiplied by 1 and sent directly to the speed regulator of the drive.
This application operates by using proportional control. The correction will be indicated in percentage according
to the line speed, from 0 to the maximum.
Program PI top limit and PI bottom limit so that the max. correction of PI block corresponds at 20% of line
speed.
PI top limit and PI bottom limit parameters are the maximum and minimum multiplier factor of Feed forward
value.
At the max. line speed it will correspond 2550rpm of the motor (max. feed-forward).
Max. correction = 2550 x 20% = 510rpm
2550 + 510 = 3060rpm ——> PI top limit = 3060 / 2550 = 1.2
2550 - 510 = 2040rpm ——> PI bottom limit = 2040 / 2550 = 0.80
which will to multiply the setting of PI central v 1 (= 1) by + 20% (1.2) and - 20% (0.80).
With this configuration, having a correction proportional to the line speed, the PI block is not able to apply ten-
sion at speed = 0. In order to apply tension in stop conditions, it is necessary to use on the PD block.
The gains of the single components have to be set with loaded machine; it is possible to start tests with values
below indicated (default values):
Set PI P gain PID = 10%
Set PI I gain PID = 10%
Set PD P gain PID = 10%
In case use the derivative component for forcing the regulator output during velocity changes of the system,
programming for example:
PD D gain PID = 5%
PD D filter PID = 20ms
If not necessary, keep these parameters = 0.
In case it is necessary to carry out a references cascade for another drive, set PID output on an analog output,
for example: