Finite Control Set Model Predictive Control Strategy of Line-Voltage Cascaded Inverter with Low-Value Inductor

In order to suppress the circulating current and avoid the instantaneous short-circuit of the DC power, the high-value current-limiting inductors are needed between the cascaded units of the line-voltage cascaded voltage source inverter (LVC-VSI). In this paper, the three cascaded units of the LVC-VSI are considered as a whole, and the interaction between the switching states of the three units is analyzed. Besides, for the purpose of reducing the value of the current-limiting inductor, the constraints of switching combinations and the equivalent circuit under the condition of no circulating current and no short-circuit are deduced. Finally, taking voltage vector satisfying the constraints as the candidate vector, a finite control set model predictive control strategy is proposed. The experimental results show that the proposed strategy can realize good performance under the condition of low-value inductor.