【摘要】 针对传统三电平逆变器供电式永磁同步电机模型预测控制应用中开关频率较高的问题,提出一种计及开关频率优化的模型预测转矩控制策略。首先,通过引入限制开关状态切换的矢量筛选策略并构建包含开关频率约束项的价值函数,在减少备选电压矢量数量的同时有效降低开关频率;然后,利用小矢量的冗余特性实现了中点电位平衡控制;最后,分别通过仿真分析和实验验证了该控制策略的有效性。仿真和实验结果表明:通过该控制策略的系统开关频率与传统策略相比降低了近一半,且消除了中点电位的波动。更多还原

【Abstract】 In order to reduce the switching frequency involved in the traditional three-level model predictive control utilized for permanent magnet synchronous motors(PMSMs), a model predictive torque control scheme associated with the switching frequency optimization is proposed. Firstly, the reason for higher switching frequency in the three-level drive system is analyzed in depth. Then, the vector screening strategy considering switching state restriction is introduced and the switching frequency constraint is constructed in the cost function, which can effectively reduce the switching frequency as well as decrease the number of candidate vectors. Furthermore, the neutral potential is balanced in terms of the opposite effect of positive and negative redundant small vectors on neutral potential. Finally, the validity of the control strategy is verified by the simulation and experiment. The simulated and experimental results prove that the switching frequency of the proposed control strategy is reduced by nearly half of that in traditional strategy;meanwhile, the fluctuation of neutral potential is eliminated.更多还原