Root Cause Analysis of Plant-Wide Oscillations in Nuclear Power Plants Based on Time-Frequency Analysis

Nuclear power represents a new type of electricity, and the safe operation of nuclear power plants is of great importance. However, in actual operation, many loops in nuclear power plants suffer from performance degradation caused by oscillations, which may lead to serious safety problems. In this paper, based on the actual situation of nuclear power plants, firstly, we construct the plant-wide loop diagrams of nuclear power plants and obtain the operation data of different loops. Then, the real-time operation data are decomposed to verify the existence of plant-wide oscillations. Finally, the clustering grouping of the loops is carried out based on the structure matrix. The root cause of the oscillations is traced within the same grouping using Granger causality analysis, and the root cause node of the oscillations is finally found. The findings of this paper provide a basis for performance improvement of control loops in nuclear power plants.