Woodward ProAct I, Product Manual

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Manual 04121 ProAct I/II
Woodward 13
Alternate Dynamics
The ProAct control provides two complete sets of dynamic adjustments, which
are externally switch selectable. The two sets of dynamics are provided for use
where engine operating conditions change, such as in systems which use two
different fuels, clutched-in loads, and electrical power generation where the unit
may be operated stand-alone and paralleled with an infinite bus.
Each set of dynamics provides different gain mapping, stability, compensation,
gain ratio, and gain window settings. This allows instantaneous changes in
control for engines which operate with different fuels or have load-type changes
which require different dynamics.
Gain Ratio is the ratio of Gain setting during transient off-speed conditions to the
gain setting at steady state. Speed Gain Ratio operates by multiplying the Gain
set point by the Gain Ratio when the speed error is anticipated to be greater than
the Window Width. This allows a lower gain at steady state for better stability and
reduced steady-state actuator movement (see Figure 2-1).
Figure 2-1. Window Width for Gain Ratio
During steady-state operation with a constant load, the control uses the base
gain setting. This gain is adjusted by the user to a value to prevent the control
from responding to minor fluctuations in engine speed, a common problem with
gas-fuel, spark-ignited engines.