Electromagnetic Performance Study of CRDM Based on Optimization Equivalent Magnetic Circuit Method

In order to establish an accurate theoretical analytical model of the control rod drive mechanism to provide a new aid for the analysis of the electromagnetic performance of the CRDM, this study establishes an accurate equivalent magnetic circuit model of the CRDM based on the distribution of the CRDM reluctance from the equivalent magnetic circuit method. With this model, the magnitude of the CRDM electromagnetic lifting force was calculated for different air gap lengths. The flux edge effect was considered and a correction factor was introduced to modify the theoretical calculation results of the electromagnetic force. Subsequent comparison with the finite element calculation results shows that the introduction of the correction factor can improve the calculation accuracy of the lifting force of the equivalent magnetic circuit method. Compared with the calculation model without considering the edge effect, the calculation accuracy of its electromagnetic force is improved by 21.2%. Therefore, the optimized equivalent magnetic circuit model established in this study can be used for the theoretical design of CRDM electromagnetic performance