基于单元级的有限控制集模型预测控制在并联三相三电平逆变器中的应用

For high-power paralleled three-phase three-level inverters with low switching frequency requirements, a novel cell-by-cell-based (CBCB) finite control set model predictive control algorithm is proposed in this article. First, the CBCB framework involves two individual inverters with staggered control timings, differing by half a period. Second, within the CBCB framework, a delay compensation solution with smaller estimation errors is expounded. Furthermore, a novel cost function for each individual inverter is designed, resulting in a doubling of the equivalent control frequency. Third, to improve the computational efficiency, candidate voltage vectors are preselected under the constraint of phase voltage jump and the requirement for low phase circulating current (PCC). Compared to the conventional decentralized FCS-MPC algorithm and the existing optimization algorithms, the proposed algorithm significantly reduces current harmonics and has a faster dynamic response rate at low average switching frequencies. Meanwhile, PCC is well suppressed. Besides, the above advantages are robust when the electric-circuit parameters are mismatched in the control system. Experimental results are provided to validate the advantages of the proposed algorithm.