Control of Permanent Magnetic Spherical Motor Based on Torque-Sharing Strategy

Abstract

In permanent magnet spherical motor control system, in order to obtain control current of the stator winding, it is required to solve the generalized inverse of the torque matrix of high dimension, which increases the computational burden of the control system. To solve this problem, the torque-sharing strategy of double-pole structure of PMSM was discussed. The target torque was decomposed into the rotation torque and the tilting torque through comparing the torque component of different stator windings. The set of control winding is divided. Further, according to the torque characteristics of a collection of internal stator winding and rotor position, an energizing strategy of the windings was developed, and the rotation and tilt torque control matrix were obtained, and two dimensional reduction matrixes reduced the computational burden. On this basis, the dynamics model and electrical model of PMSM were established, and the control system consisted of position loop and current loop. Control torque was obtained by the calculation of the torque method, and control current was obtained by torque-sharing strategy. Simulation results show that the system is able to achieve independent control of rotation and tilt and track the desired trajectory.