Study on Electromagnetic Structure Design of Linear Motor Type Reactor Control Rod Drive Mechanism

The electromagnetic structure design is the core of the design of control rod drive mechanism (CRDM) for electromagnetic reactors. This study introduces a cylindrical linear motor suitable for the CRDM. Firstly, this study describes the basic electromagnetic structure of such motor. Secondly, in an analytical calculation method, the feasible slot-pole combination is derived and a new concentrated winding structure is analyzed. Thirdly, further study is performed on the key factors affecting the performance indexes of the CRDM, including the slot-pole combination, winding structure form, and electromagnetic structure dimensions, in the 2D finite element method (FEM). Finally, based on the further study results, the detailed design and test & verification of the electromagnetic structure are carried out. The test results show that the linear motor type CRDM is designed reasonably, and can perform the basic functions, such as lifting, inserting downward, holding and dropping, in accordance with the control commands, and that its technical specifications, such as the lifting force, following characteristic and rod drop performance, can meet the design requirements.