Performance Evaluation Method and System of Control Rod Drive Mechanism Based on Action Critical Sequence

Abstract

The invention discloses a method for evaluating the performance of a control rod drive mechanism based on the key sequence of actions, which includes: acquiring current related signals and vibration signals for a period of time; performing periodic division to obtain N complete CRDM rod lifting signals; extracting key points of the sequence, Form a feature vector; establish a decision function, and obtain the reference distance of the normal signal through the decision function; obtain real-time current-related signals and vibration signals, and divide the obtained current-related signals and vibration signals into periods to obtain the CRDM lifting stick signal at the current moment; Extract real-time timing key points to form feature vectors; establish the current data decision function to obtain the difference between the current feature vector and the reference distance of the normal signal, and judge whether the control rod drive mechanism has performance degradation according to the difference. The invention can realize the online performance evaluation of CRDM, and is helpful to realize the predictive maintenance of CRDM equipment; can automatically realize the period division of the original CRDM signal, and solves the difficult problem of online monitoring.

Description

technical field [0001] The present invention relates to the technical field of performance evaluation, in particular to a method and system for evaluating the performance of a control rod driving mechanism based on the key action sequence. Background technique [0002] Control rod drive mechanism (Control Rod Drive Mechanism, CRDM) is a kind of servo mechanism of nuclear power plant reactor control system and safety protection system, among which the magnetic lifting type CRDM is the most commonly used mechanism type at present. Since CRDM is the only movable part in the nuclear reactor pressure vessel, its failure or performance degradation will directly lead to accidents such as stuck rods and out-of-step, which will seriously affect the safe and reliable operation of the unit. Therefore, it is necessary to use real-time monitoring means to evaluate the online performance of CRDM, and find its performance degradation trend as early as possible. After reviewing relevant in...

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Problems solved by technology

After reviewing relevant information, it is found that there is no clear technical literature on online evaluation of CRDM performance at this stage, and general research focuses on the offline fault diagnosis of CRDM through current signal analysis.

In addition, as an important part of controlling the operation of nuclear reactors, CRDM has a compact mechanical structure, harsh working environment and strict safety standards, so the reliability of the monitoring scheme is much higher than that of general mechanical equipment, which also affects the type, quantity and installation of sensors. method puts forward more restrictive requirements

Not only is the online monitoring result not accurate enough, but the error will be large

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