Drive Current Calculation and Analysis of Permanent Magnet Spherical Motor Based on Torque Analytical Model and Particle Swarm Optimization

In order to determine the currents required in different attitudes and torque target conditions, this paper proposes a calculation method for drive currents of permanent magnet spherical motors based on three-dimensional magnetic field, torque analytical model and optimization algorithm. Firstly, an electromagnetic torque analytical model base on equivalent surface currents of a permanent magnet and Lorentz force is proposed. The feasibility and accuracy are verified by comparing results with those by the finite element method. Then, an inverse calculation model of the motor drive current is built by combining the torque analytical model with the Particle Swarm Optimization (PSO) algorithm. At last, using the proposed drive current calculation model, the driving current characteristics of spherical motors under different energization strategies are compared and analyzed.