计及开关频率分区优化的PMSM三电平模型预测控制

为降低传统三电平供电的永磁同步电机模型预测控制系统的开关频率，提出一种计及开关频率分区优化的PMSM三电平模型预测控制方法。首先，将空间电压矢量平面划分为12个扇区，并且根据上一时刻电压矢量所在位置，选择相邻扇区的电压矢量作为备选矢量。其次，加入对开关状态切换的限制，每个开关周期仅允许一相开关状态发生连续性跳变，减少备选矢量数量的同时能够有效降低开关频率。进一步，利用具有相同空间位置但对中点电位影响相反的正负冗余小矢量来平衡中点电位。最后，通过仿真和实验，验证该控制策略的有效性。

Three-level Model Predictive Control of PMSM Based on Subregion Switching Frequency Optimization

To reduce the switching frequency of the traditional three-level permanent magnet synchronous machine(PMSM) model predictive control(MPC) system, a three-level MPC method for PMSM based on subregion switching frequency optimization is proposed in this paper. First, the space voltage vector plane is divided into 12 sectors, and the voltage vectors in adjacent sectors are selected as candidates according to their positions at the previous time. Then, the restriction on switching state is added, so that only one phase switch is allowed to be changed continuously in each switching period, which can effectively decrease the switching frequency while reducing the number of candidate vectors. Furthermore, the midpoint potential balance can be achieved by utilizing the negative and positive redundant small vectors that have the same space position but exert opposite effects on the midpoint potential. Finally, both simulation and experimental results verified the effectiveness of the proposed control strategy.