Multi-cell topology based on voltage-source converters with a reduced DC Capacitor by means of a predictive control scheme

Multi-cell topologies based on three-phase input/singlephase output power modules have the drawback of dealing with an important oscillatory power in the DC link. This requires the use of a large DC link capacitor in order to minimize the DC link voltage ripple. Instead, this paper proposes a control scheme based on predictive control aimed to compensate the oscillatory power that allows the design of the DC link capacitor without oversizing it. However, this is achieved at expense of much distorted AC supply currents and amplified modulating signals. Such effects of the proposed compensating technique based on predictive control are mathematically characterized. The results show that the multi-pulse transformer guarantees distortion free overall AC currents. Simulated results show the feasibility of the proposed scheme.