ABB 800xA Operation page 100

Performance indices
Sl.No Name
21. Oscillation Index
on Control Error
22. Oscillation Index
on Setpoint
23. Oscillating Period
24. Oscillation
Amplitude
25. Oscillation Severity
Index
26. Oscillation
Amplitude
Regularity Index
100
Section 8 Control Loop Asset Monitor (CLAM)
Table 9. Indices used in CLAM
Description
Detects and quantifies oscillating signals. The
result is in the interval [-1...1] where a positive
value means that an oscillation was found and
the closer to one the value is the more regular
is the oscillation. Nominal: a value < 0. A value
> 0.5 indicates a quite regular oscillation.
This index is a pre-requisite for several other
indices to be calculated.
Detects oscillations of setpoint that is important
for detecting external excitation in a control
loop. As for the Oscillation Index on Control
Error above the result is in the interval [-1...1]
where a positive value indicates an oscillation.
Index estimating oscillation period. Can be
useful for more detailed analysis. [0...Inf].
Estimates the average amplitude of a loop that
has been found oscillating. Useful for more
detailed analysis. [0...100%].
Index presenting an analysis of how much the
signal power is related to the oscillation when
noise effects have been removed (signal
spectrum estimation). [0...100%].
Quantifies the regularity of the oscillation
amplitude. The result is a ratio between the
standard deviation of the amplitudes of all half
periods compared to their mean. [0...100 %].
Nominal: Oscillations are always not good, but
a value below 60 % is considered non-regular.
Index class
Oscillation
Oscillation
Oscillation
Oscillation
Oscillation
Oscillation
3BUA000150-600