Model Predictive Torque Control of a Novel Multilevel Power Converter for Four-Phase SRMs

In this article, a new five-level power converter and an improved model predictive control (MPC) strategy are proposed for a four-phase switched reluctance machine (SRM) to improve its output performance. Compared with the conventional four-phase three-level asymmetric half-bridge (AHB) power converter, the new power converter can achieve five voltage levels of output without increasing power devices. An improved MPC method is proposed by incorporating new operating modes and constructing a cost function associated with vector selection to further reduce torque ripple. The effectiveness of the proposed topology and control method was evaluated experimentally under different operating conditions. The experimental results show that compared with the conventional AHB power converter and existing control methods, the torque ripple can be reduced by at least 29.36% and the efficiency can be improved by 28.50% using the proposed converter structure and its MPC strategy.