Pit Detection in Current Monitoring of Control Rod Drive Mechanism Based on Daubechies Wavelet Analysis

Control rod drive mechanism is an important part of nuclear reactor. The power regulation of nuclear reactor is accomplished by control rod. The safe and effective operation of the control rod driving mechanism is the premise to ensure the normal operation of the nuclear reactor. This paper first introduce the basic structure and driving principle of the control rod drive mechanism, and explains the cause of trough in the coil current signal during normal operation. Secondly, the acquisition and display of current signals are completed through the hardware acquisition system. Then, the timing sequence of the changes of the current signals of the three coils and the completion of their actions are analyzed. Finally, the intelligent diagnosis of the control rod drive mechanism is realized by detecting the trough in the current signal through the Daubechies Wavelet analysis.