Paralleling Gain Setting - Kohler 14EKOZD Installation Manual

9.3.2

Paralleling Gain Setting

The Decision-Makerr 3500 controller is preset with
factory defaults for each generator model number in the
personality profile. These gains should perform
adequately for most applications, but it may be
necessary to perform adjustment of advanced settings.
The Decision-Makerr 3500 controller uses PID
(Proportional, Integral, and Derivative) type gains as
explained below:
Proportional gain controls the response time or
D
sensitivity when a change, due to an error, is
needed. Too high or too low of a gain value can
create instability as it can make the system too
sensitive or damped. Too sensitive of a gain value
makes the control loop "chase" the target. A small
gain makes the control loop slow to respond to a
target change. Proportional gain is the primary
component in making an output change.
Integral gain controls how aggressive the output
D
change will be. Too high of a gain value can cause
an overshoot of the target when an output change
is needed. This gain should start small and in some
instances will be a fairly small value when
compared to the proportional or derivative gains.
Derivative gain controls the overshoot and
D
settling time of an output change. Too low of a gain
value can cause "ringing" or oscillation of an output
change as the target is met. Derivative gain may
not be needed in some installations as the
proportional and integral gains do the bulk of the
work on an output change. If the system has some
instability after an output change that eventually
goes away, increase the derivative gain.
TP-7045 3/18c
Tuning Example
Before beginning, ensure that all generator set
controllers are connected to a PC via a USB cable and
that all controllers are shown in SiteTecht under the
"Manage Parallel Devices" mode located at the top of
the SiteTecht screen.
Note: For more information on SiteTecht, see
TP-6701 SiteTecht Software Operation Manual.
If the factory-set gains are deemed inadequate, the Real
Power Load Sharing gains are most likely the gains that
need adjustment. Synchronizing parameters like phase
match window, synchronization frequency match
window, and voltage match window and their associated
gains are factory-set and should not need adjustment.
Monitoring Generator Total Real Power (located in the
Generator Metering tab in SiteTecht) on all paralleled
generator sets simultaneously and observing the
behavior of a changing load condition provides an
indication of whether an adjustment is needed. If the
paralleled generator sets are able to share load at
varying load steps without errors, the proportional gain
is likely ok. Some shift of load from generator set to
generator set is normal, but the actual kW of load
movement should be minimized.
movement is observed from generator set to generator
set, start by decreasing the integral gain. If the load shift
is happening at a high frequency, increase the derivative
gain. In general, increasing the derivative gain makes
the load shift happen slower. Reducing the integral gain
makes the amplitude of the load being shifted smaller.
Reactive Power Load Sharing gains can be adjusted in
the same way (monitor Generator Total Reactive Power
located in the Generator Metering tab in SiteTecht), but
it's unlikely that the factory gains will need any
adjustment. Always start with the Real Power Load
Sharing gains.
Any of the other Decision-Makerr 3500 controller PID
gains can be adjusted using the same method explained
above, however note that the derivative gains for most
other parameters are disabled from the factory.
Note: All factory gains are values of 1 so it is simple to
revert back to the factory defaults.
Section 9 Paralleling Generator Sets
If a large load
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