A systematic method to identify nonlinear dynamics of BWR by using the reactor noise
Autor: | Liu Wenfeng, Luo Zhengpei, Wang Yaqi, Li Fu |
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Rok vydání: | 2003 |
Předmět: |
Damping ratio
System identification Energy Engineering and Power Technology Natural frequency Nonlinear system Noise Nuclear Energy and Engineering Parametric model Applied mathematics Autoregressive–moving-average model Safety Risk Reliability and Quality Waste Management and Disposal Impulse response Mathematics |
Zdroj: | Progress in Nuclear Energy. 43:209-216 |
ISSN: | 0149-1970 |
DOI: | 10.1016/s0149-1970(03)00030-1 |
Popis: | For the identification of the dynamics of the Vermont Yankee BWR with the reactor noise, different parametric models have been tested. The widely used ARMA model is unable to identify the nonlinearity in the noise data. A systematic method by using the NARMA model, which takes advantage of both the ANN and ARMA, is developed. Comparisons are made between the identification results with ARMA and NARMA model. The advantages of identification with NARMA model over ARMA model are demonstrated. The linear-kernels of the identified NARMA models are extracted so that the natural frequency, damping ratio and time constants of the BWR are obtained. The values of those characteristics are well corresponded with the eigenvalues calculated by the differential equations of the Vermont Yankee BWR. The damping ratio with negative value is found to be a criterion for the existence of limit-cycle, which can be seen from the impulse response on the (X t , X t-1 ) plane, in stable nonlinear system. |
Databáze: | OpenAIRE |
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