Parker 650V series, Техническое руководство

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Programming Your Application
6-15
650V AC Drive
A Method for Setting-up the PI Gains
The gains should be set-up so that a critically damped response is achieved for a step change in
setpoint. An underdamped or oscillatory system can be thought of as having too much gain, and
an overdamped system has too little.
To set up the P gain, set the I gain to zero. Apply a step change in setpoint that is typical for the
System, and observe the response. Increase the gain and repeat the test until the system becomes
oscillatory. At this point, reduce the P gain until the oscillations disappear. This is the maximum
value of P gain achievable.
If a steady state error is present, i.e. the feedback never reaches the setpoint value, the I gain
needs to be increased. As before, increase the I gain and apply the step change. Monitor the
output. If the output becomes oscillatory, reduce the P gain slightly. This should reduce the
steady state error. Increasing the I gain further may reduce the time to achieve zero steady state
error.
These values of P and I can now be adjusted to provide the exact response required for this step
change.
Auto Restart
Parameters
S
ST21 to
S
ST24 provide the facility to automatically reset a choice of trip events and
restart the drive with a programmed number of attempts. If the drive is not successfully started,
a manual or remote trip reset is required.
The number of attempted restarts are recorded. This count is cleared after a trip-free period of
operation (5 minutes or 4 x AUTO RESTART DELAY, whichever is the longer); or after a
successful manual or remote trip reset; or by removing the Run signal (Terminal 7, DIN1).
Refer to Chapter 7: "Trips and Fault Finding" - Hexadecimal Representation of Trips.
Minimum Speed Mode
There are two operating modes for the minimum
speed feature.
Proportional with Minimum
In this mode the speed setpoint is clamped to be
between the minimum speed value (P3) and 100%.
This is the default for the minimum speed feature.
Linear
In this mode the speed setpoint is first clamped to
be in the range 0 to 100%. It is then rescaled so
that the output goes linearly between the
minimum speed value (P3) and 100% for an input
setpoint that goes between 0% and 100%. If the
minimum speed value (P3) is negative the speed
setpoint will be internally set to 0%.
Min
0 100%
100
-100
input
output
100
Min
0 100%
output
input
200%
max =
300.00% – (2 x min)
Underdamped (oscillatory) Critically Damped
Overdamped
OUTPUT
SETPOINT