传统三电平整流器模型预测控制算法需要对全部27个开关矢量进行在线评估,使价值函数最小的开关矢量在下一采样周期采用.然而该算法在实际实现时计算量较大,限制系统采样周期的降低,从而制约了系统整体性能的提高.本文提出了一种简化的三电平整流器模型预测控制算法,根据参考电压矢量所在扇区信息,仅选取该扇区内的开关状态进行评价.简化算法不仅大大减少了程序计算量,还获得了良好的静态和动态性能.最后实验验证了该方案的正确性和实用性,能获得良好的静态和动态特性.
In the conventional model of predictive control of three-level rectifier, the twenty-seven switching vectors for three-level rectifier are evaluated on line based on a discrete-time model of the system, and the vector that makes the cost function smallest will be applied in the next sampling period. But in the practical implementation, the conventional method can lead to a huge amount of calculations, which contradicts the requirements of the possi- ble low sampling periods since it greatly improves the overall performance of MPC. In order to solve the problem, a simplified model predictive method is proposed in this paper. Utilizing the sector information of the reference volt- age space vector, the proposed method just evaluates the switching states in the sector. The computational effort has been greatly reduced while the steady-state performance and dynamic response of the current control are improved. The feasibility and correctness of the control strategy are verified by experimental results at last.