This article proposes a fixed switching frequency predictive control method for neutral point clamped (NPC) single-phase PWM rectifier to achieve global optimization of the current during the entire switching cycle. Through the optimization of the switching sequence, a three-stage switching sequence that can control the midpoint potential balance is obtained. The extreme point, the initial point, and the end point of the current error within the switching period are employed to establish an error matrix, and the error matrix ℓ2-norm minimality is considered as the optimization objective. This optimization problem is a convex optimization problem, and the optimal duty cycle of the switching sequence can be obtained by solving the convex problem. The optimal duty cycle of each feasible switching sequence is obtained, and then the switching sequence that minimizes the error matrix ℓ2-norm is selected as the system output among all feasible switching sequences. Finally, the experimental results show that the proposed control scheme has good performance.

中文翻译：

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基于电流凸优化的固定开关频率单相三电平PWM整流器预测控制


本文提出了一种中性点钳位（NPC）单相 PWM 整流器的固定开关频率预测控制方法，以实现整个开关周期内电流的全局优化。通过对开关顺序的优化，得到了能够控制中点电位平衡的三级开关顺序。利用切换周期内电流误差的极值点、起始点和终点建立误差矩阵，并以误差矩阵ℓ2范数极小为优化目标。该优化问题是凸优化问题，通过求解凸问题即可得到开关序列的最优占空比。获得每个可行开关序列的最优占空比，然后在所有可行开关序列中选择误差矩阵ℓ2-范数最小的开关序列作为系统输出。最后，实验结果表明，所提出的控制方案具有良好的性能。