基于线段近似法的姿态控制线圈磁场位形研究

Magnetic field configuration of attitude control coil based on line segment approximation method

基于线段近似方法对几何结构相对复杂的偶极场姿态控制(Tilt-Slide-Rotate coils,TSR)线圈的线圈作用力进行了研究。在偶极场倾斜和偏移情况下,分别通过控制对侧和同侧TSR线圈产生磁力使偶极场线圈恢复平衡位置的情形进行了建模分析。计算TSR线圈和偶极场线圈耦合磁场及分析磁场线结构,并采用具有正弦电流形式的TSR线圈激励磁场模拟环向磁扰动,对扰动磁场在赤道面上的庞加莱截面图的磁场线结构和相位进行分析。发现仅通过一组同侧或对侧TSR线圈控制偶极场线圈使其恢复平衡时该过程具有力学不稳定性,需要多组TSR线圈协同控制。对全部TSR线圈施加伪正弦电流,会对背景偶极磁场产生压缩和拉伸效应,并且控制TSR线圈电流来控制压缩位置相位,该过程验证了多TSR线圈控制偶极场线圈姿态的可行性,但同时会使背景磁场发生漂移及形成开放磁场线,这可能会驱动等离子体不稳定性及导致粒子的损失。

[Background]When the suspended dipole field coils experience significant disturbances during the operation of the suspended dipole field device,the Tilt-Slide-Rotate(TSR)coils are used to control the attitude of the dipole field coils,thereby preventing them from losing control.[Purpose]This study aims at attitude control of dipole fields by coil forces of the TSR coils with relatively complex geometric structures.[Methods]Based on the line segment approximation method,the modeling and analysis were conducted for scenarios where the dipole field coils return to their balanced position under conditions of dipole field tilt and offset by controlling the magnetic forces generated by the TSR coils on both opposite and same sides.The coupling magnetic field between the TSR coils and the dipole field coils was calculated,and the magnetic field line structure was analyzed.The excitation magnetic field of the TSR coils,in the form of sinusoidal currents,was simulated to induce azimuthal magnetic disturbances.Analysis was performed on the magnetic field line structure and phase of the perturbation magnetic field on the Poincarésection at the equatorial plane.[Results and Conclusions]If only one group of TSR coils on the same or opposite sides is used to control the dipole field coils to restore equilibrium,exhibited mechanical instability needs necessitating coordinated control by multiple sets of TSR coils.Applying pseudo-sinusoidal currents to all TSR coils induces compression and stretching effects on the background dipole magnetic field.By controlling the current of the TSR coils to control the phase of the compression position,the feasibility of controlling the attitude of the dipole field coils with multiple TSR coils has been validated.However,this process may also cause drift in the background magnetic field and the formation of open magnetic field lines,which could drive plasma instabilities and lead to particle loss.