降低永磁球形电机铜耗的通电策略研究

Research on Energization Strategy to Reduce the Copper Loss of the Permanent-magnet Spherical Motor

连续运行模式下,针对永磁球形电机(Permanent-magnet spherical motor,PMSpM)恶劣的通风、冷却条件影响电机可靠运行和使用寿命的问题,提出了几种能够精确输出目标转矩并避免局部过热的自旋通电策略。建立了基于有限元分析(Finite-element analysis,FEA)的单线圈电流有效值-稳态温度(IRMS-Tsteady)模型,提出使用高精度电流传感器间接测量线圈温度的方法,以验证模型的准确性。基于此分析了偏心自旋、最小电流和、固定励磁线圈三种通电策略。后两种策略采用改进的粒子群优化(Particle swarm optimization,PSO)算法优化驱动电流,算法通过参数方程限制粒子产生与更新以精确输出目标转矩,并分别尝试通过减少粒子维度和指定线圈组合来进一步降低铜耗。策略对比结果表明,固定励磁线圈策略能够在输出目标转矩的前提下大大降低铜耗且避免了局部热点出现。

In continuous operation mode,aiming at the problem that the harsh ventilation and cooling conditions of permanent-magnet spherical motor(PMSpM)affect the reliable operation and service life of the motor,several spin energization strategies that can output target torque exactly and avoid local overheating are proposed.A model of relationship between effective value of single coil current and steady-state temperature(IRMS-Tsteady)based on finite-element analysis(FEA)is established,and a method of indirectly measuring the coil temperature using a high-precision current sensor is proposed to verify the accuracy of the model.Based on this,three energization strategies of eccentric spin,minimum current sum and fixed excitation coils are analyzed.The latter two strategies use improved particle swarm optimization(PSO)algorithms to optimize the drive current,which limit particle generation and update through parametric equations to output target torque accurately,and try to further reduce copper loss by reducing particle dimensions and specifying coil combinations,respectively.The strategy comparison results show that the fixed excitation coils strategy can greatly reduce copper loss and avoid local hot spots on the premise of outputting the target torque.