Determining the maximum Lyapunov exponent from measured time series data

Conference · Tue Jan 01 04:00:00 EST 1991 · Transactions of the American Nuclear Society; (United States)

OSTI ID:7074772

Clapp, Jr, N E ^[1]

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1. Oak Ridge National Lab., TN (United States)

It has been shown that a time series is chaotic if it contains at least one positive Lyapunov exponent. To use this information for signal classification, a technique is needed to estimate the largest Lyapunov exponent from time series data. A technique for estimating the maximum Lyapunov exponent from measured time series data has been developed using phase portraits, which are constructed using the method of delays. This paper briefly describes the technique and applies it to pressure sensor data from a once-through steam generator (OTSG) at a nuclear power plant. It is desirable to avoid chaotic flow conditions in order to minimize vibratory stress on the tube bundle of the OTSG. Using this technique, chaotic behavior was detectable using data taken by the plant computer with a 1-s sampling interval. This technique shows the potential for use in advanced surveillance and diagnostic systems to detect chaotic behavior in nuclear power plants.

• OSTI ID: 7074772
• Report Number(s): CONF-911107--
• Conference Information: Journal Name: Transactions of the American Nuclear Society; (United States) Journal Volume: 63
• Country of Publication: United States
• Language: English

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