An Output-Bounded Model Predictive Control with Equivalently Variable Sampling Interval for Current-Source Converter

In this study, an output-bounded model predictive control (MPC) with equivalently variable sampling interval for current-source converter (CSC) is proposed to realize low switching frequency control in high power medium-voltage (MV) applications. In contrast to conventional MPC for CSC with reduced switching frequency, there is no weighting factor selection issue in the proposed scheme, and three-phase load currents in a CSC can be regulated inside pre-defined output bounds around three-phase load current references. Compared to other MPCs with low switching frequency, the proposed scheme still belongs to one-step prediction method, which does not require multistep prediction, and reduces the final calculation burden. The proposed scheme has been validated through simulation on a high power MV CSC (1MV/4160V/139A).