A new fuzzy-logic-based methodology for on-line signal trend identification
is introduced The methodology may be used for detecting the onset of nucle
ar power plant (NPP) transients at the earliest possible time and could be
of great benefit to diagnostic, maintenance, and performance-monitoring pro
grams. Although signal trend identification is complicated by the presence
of noise, fuzzy methods can help capture important features of on-line sign
als, integrate the information included in these features, and classify inc
oming NPP signals into increasing, decreasing, and steady-state trend categ
ories. A computer program named PROTREN is developed and tested for the pur
pose of verifying this methodology using NPP and simulation data. The resul
ts indicate that the new fuzzy-logic-based methodology is capable of detect
ing transients accurately, it identifies trends reliably and does not misin
terpret a steady-state signal as a transient one.